chore: consider switching JSON-schema dependency to github.com/santhosh-tekuri/jsonschema

[thaJeztah]

Description

• related: chore: consider switching JSON-schema dependency to github.com/santhosh-tekuri/jsonschema compose-spec/compose-go#749

The github.com/xeipuuv/gojsonschema module used for JSON-schema validation has not been maintained for a long time, and because of that, ended on the "avoid" list in kubernetes; kubernetes/kubernetes#128572 (comment)

The OCI image-spec has now transitioned to a new dependency (github.com/santhosh-tekuri/jsonschema) as replacement in v1.1.1, and we should look if we can follow so that we don't end up with two separate dependencies performing the same task;

• Switch jsonschema validation libraries opencontainers/image-spec#1189