[CI] Validate pipeline resource definitions and location collection (#208398)

## Summary
This PR adds quick-checks regarding pipeline resource definitions. 
- Adds validation/correction for `locations.yml`
- Adds validation for definitions (through
`docker.elastic.co/ci-agent-images/pipelib rre validate`).
- Also fixes a missing pipeline entry in `locations.yml`

Example for when a YML error bounces on schema validation:
https://buildkite.com/elastic/kibana-pull-request/builds/270652#0194a8d5-48df-4f1b-8ec7-1f076851d138
Example for auto-fixing missing location:
b2170ac53a

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

.buildkite/pipeline-resource-definitions/locations.yml

@@ -17,6 +17,7 @@ spec:
     - https://github.com/elastic/kibana/blob/main/.buildkite/pipeline-resource-definitions/kibana-codeql.yml
     - https://github.com/elastic/kibana/blob/main/.buildkite/pipeline-resource-definitions/kibana-console-definitions-sync.yml
     - https://github.com/elastic/kibana/blob/main/.buildkite/pipeline-resource-definitions/kibana-coverage-daily.yml
+    - https://github.com/elastic/kibana/blob/main/.buildkite/pipeline-resource-definitions/kibana-deploy-cloud.yml
     - https://github.com/elastic/kibana/blob/main/.buildkite/pipeline-resource-definitions/kibana-deploy-project.yml
     - https://github.com/elastic/kibana/blob/main/.buildkite/pipeline-resource-definitions/kibana-es-forward-testing-9-dot-0.yml
     - https://github.com/elastic/kibana/blob/main/.buildkite/pipeline-resource-definitions/kibana-es-forward-testing.yml

.buildkite/pipeline-resource-definitions/scripts/validate-pipeline-definition.sh

@@ -15,7 +15,7 @@ ABSOLUTE_PATH=$(realpath "$TARGET_FILE")
 FILE_NAME=$(basename "$ABSOLUTE_PATH")
 FOLDER_NAME=$(dirname "$ABSOLUTE_PATH")
 
-docker run -it \
+docker run \
  --mount type=bind,source="$FOLDER_NAME",target=/home/app/ \
   docker.elastic.co/ci-agent-images/pipelib:0.8.0@sha256:641d7fc6cfe473900a1fbe49876762916d804b09fdf2945f74e9f803f3073779 \
   rre validate --backstage-entity-aware "/home/app/$FILE_NAME"

.buildkite/scripts/steps/checks/quick_checks.txt

@@ -20,3 +20,4 @@
 .buildkite/scripts/steps/checks/test_files_missing_owner.sh
 .buildkite/scripts/steps/checks/styled_components_mapping.sh
 .buildkite/scripts/steps/checks/dependencies_missing_owner.sh
+.buildkite/scripts/steps/checks/validate_pipelines.sh

.buildkite/scripts/steps/checks/validate_pipelines.sh

@@ -0,0 +1,23 @@
+set -euo pipefail
+
+source .buildkite/scripts/common/util.sh
+
+echo --- Check if all pipelines are in locations.yml
+cmd="ts-node .buildkite/pipeline-resource-definitions/scripts/fix-location-collection.ts"
+
+eval "$cmd"
+check_for_changed_files "$cmd" true
+
+if [[ "${BUILDKITE_PULL_REQUEST_BASE_BRANCH:-}" != "" ]]; then
+  echo --- Check if all new pipelines are valid
+  AFFECTED_PIPELINES=$(git diff "$BUILDKITE_PULL_REQUEST_BASE_BRANCH" --name-only | \
+    grep -E '^.buildkite/pipeline-resource-definitions/.*\.yml$' | \
+    grep -Ev '(/locations.yml|_templates)' || true)
+  echo "Pipelines affected by this PR: $AFFECTED_PIPELINES"
+
+  for pipeline in $AFFECTED_PIPELINES; do
+    .buildkite/pipeline-resource-definitions/scripts/validate-pipeline-definition.sh "$pipeline"
+  done
+fi
+
+exit 0