ci: only run catlin validate when a resource manifest changes

catlin (all versions through HEAD) only registers the tekton.dev/v1beta1
scheme and cannot parse tekton.dev/v1 resources, failing with:

  no kind "Task" is registered for version "tekton.dev/v1"

See tektoncd/catlin#10. The catalog already ships 37 tekton.dev/v1
Tasks. Normal PRs touch a single task and rarely a v1 one, so this went
unnoticed. A broad, README-only PR touching nearly every task directory
makes the catlin validate gate reduce every changed file to its version
directory and validate the whole catalog, hitting v1 resources catlin
cannot parse.

Filter the changed-file set to resource manifests that live directly in
a version directory (task/<name>/<version>/*.yaml) before reducing to
the version directory. README/OWNERS-only changes, test manifests under
tests/, and files under samples/ no longer trigger validation, so a
docs-only change validates nothing and does not fail on catlin's missing
v1 support.

Signed-off-by: Vincent Demeester <vdemeest@redhat.com>

Author: vdemeester

.github/workflows/ci.yaml

@@ -49,18 +49,21 @@ jobs:
       env:
         PULL_BASE_SHA: ${{ github.event.pull_request.base.sha }}
       run: |
-        # Detect changed task version directories (task/<name>/<version>).
-        # Reduce every changed file to its version directory so that catlin
-        # only validates the catalog resource itself, never the test
-        # manifests under tests/ (TaskRun/Pipeline) or files under samples/,
-        # which are not catalog resources and would fail validation.
+        # Detect task version directories (task/<name>/<version>) whose
+        # resource manifest changed. Only consider YAML files that live
+        # directly in the version directory (task/<name>/<version>/*.yaml);
+        # this excludes README/OWNERS-only changes as well as the test
+        # manifests under tests/ (TaskRun/Pipeline) and files under samples/,
+        # none of which are catalog resources. Reducing to the version
+        # directory means catlin only ever validates the catalog resource.
         changed_tasks=$(
           git --no-pager diff --name-only ${PULL_BASE_SHA}..HEAD | \
+          { grep -E '^task/[^/]+/[^/]+/[^/]+\.yaml$' || true; } | \
           { grep -oE '^task/[^/]+/[^/]+' || true; } | \
           sort -u
         )
         if [[ -z "$changed_tasks" ]]; then
-          echo "No file changes detected in task directories"
+          echo "No changed task resource manifests detected"
           exit 0
         fi
         # Filter out removed directories
@@ -78,15 +81,16 @@ jobs:
       env:
         PULL_BASE_SHA: ${{ github.event.pull_request.base.sha }}
       run: |
-        # Detect changed task version directories (task/<name>/<version>).
+        # Detect task version directories whose resource manifest changed.
         # See the note in the "catlin validate" step above.
         changed_tasks=$(
           git --no-pager diff --name-only ${PULL_BASE_SHA}..HEAD | \
+          { grep -E '^task/[^/]+/[^/]+/[^/]+\.yaml$' || true; } | \
           { grep -oE '^task/[^/]+/[^/]+' || true; } | \
           sort -u
         )
         if [[ -z "$changed_tasks" ]]; then
-          echo "No file changes detected in task directories"
+          echo "No changed task resource manifests detected"
           exit 0
         fi
         # Script linting is informational (matching previous Prow behavior)