Ensure keys in redirect.yml get validated as relative to docset.yml

[Mpdreamz]

This has caused some bad redirects to be added to redirect.yml files because our checks were forcing folks to add the relative to the root instead.

Problematic redirects appear isolated to elasticsearch's redirect.yml

Submitted a PR here to clean that up: elastic/elasticsearch#134443

Elasticsearch added a bunch of redirects because _snippets were reported as missing

Reporting on _snippets was already fixed as per: #1782

From redirects.json from assemble build:

  "/docs/docs/reference/query-languages/esql/_snippets/functions/description/st_geohash_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/description/st_geotile_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/description/st_geohex_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/description/st_geohash_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/description/st_geotile_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/description/st_geohex_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/examples/st_geohash_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/examples/st_geotile_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/examples/st_geohex_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/examples/st_geohash_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/examples/st_geotile_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/examples/st_geohex_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/layout/st_geohash_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/layout/st_geotile_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/layout/st_geohex_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/layout/st_geohash_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/layout/st_geotile_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/layout/st_geohex_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/parameters/st_geohash_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/parameters/st_geotile_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/parameters/st_geohex_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/parameters/st_geohash_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/parameters/st_geotile_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/parameters/st_geohex_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/types/st_geohash_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/types/st_geotile_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/types/st_geohex_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/types/st_geohash_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/types/st_geotile_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/_snippets/functions/types/st_geohex_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/images/functions/st_geohash_to_string.svg": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/images/functions/st_geotile_to_string.svg": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/images/functions/st_geohex_to_string.svg": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/images/functions/st_geohash_to_long.svg": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/images/functions/st_geotile_to_long.svg": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/images/functions/st_geohex_to_long.svg": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/definition/functions/st_geohash_to_string.json": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/definition/functions/st_geotile_to_string.json": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/definition/functions/st_geohex_to_string.json": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/definition/functions/st_geohash_to_long.json": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/definition/functions/st_geotile_to_long.json": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/definition/functions/st_geohex_to_long.json": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/docs/functions/st_geohash_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/docs/functions/st_geotile_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/docs/functions/st_geohex_to_string": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/docs/functions/st_geohash_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/docs/functions/st_geotile_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",
  "/docs/docs/reference/query-languages/esql/kibana/docs/functions/st_geohex_to_long": "/docs/reference/query-languages/esql/esql-functions-operators",