docs: fix broken Deno.test.each API reference links

[bartlomieju]

The testing guide and the deno test CLI page linked Deno.test.each to
/api/deno//Deno.test.each, but the reference generator never emits a page
at that URL: each is a property of the DenoTest interface, so its page is
/api/deno//Deno.DenoTest.each (same pattern as the existing
Deno.DenoTest.beforeEach page). The links now point there, and oldurls.json
redirects the already-published Deno.test.each URL to the right page.

The symbol is also missing from the deployed API reference because it was
generated with a pre-2.9 Deno (the each types landed in 2.9.0). In CI the
lint workflow cached reference_gen/types keyed only on repo files, so the
types produced by deno types were never refreshed when the Deno binary
changed. The workflow now regenerates types on every run and caches only
the doc generation, keyed on the generated types' content. The deployed
reference will pick up the new page on the next build with Deno >= 2.9.

Fixes #3389