ci(docs): pin crd-ref-docs version to avoid upstream changes (#724)

Pin crd-ref-docs to v0.2.0 (latest stable release) instead of using the
master branch. This prevents issues from upstream changes and provides
better control over when to adopt new versions.

Configure Renovate to automatically track and update the version,
allowing us to review and test changes before merging.

Closes #722

Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>

Author: mnencia

Taskfile.yml

@@ -85,9 +85,13 @@ tasks:
     env:
       # renovate: datasource=git-refs depName=crd-gen-refs lookupName=https://github.com/cloudnative-pg/daggerverse currentValue=main
       DAGGER_CRDGENREF_SHA: ee59e34a99940e45f87a16177b1d640975b05b74
+      # renovate: datasource=go depName=github.com/elastic/crd-ref-docs
+      CRDREFDOCS_VERSION: v0.2.0
     cmds:
       - >
-        GITHUB_REF= dagger -s call -m github.com/cloudnative-pg/daggerverse/crd-ref-docs@${DAGGER_CRDGENREF_SHA} generate
+        GITHUB_REF= dagger -s call -m github.com/cloudnative-pg/daggerverse/crd-ref-docs@${DAGGER_CRDGENREF_SHA}
+        --version ${CRDREFDOCS_VERSION}
+        generate
         --src .
         --source-path api/v1
         --config-file hack/crd-gen-refs/config.yaml