fix(ci): restore original version.yml workflow logic

Accidentally replaced workflow logic when only the filename should have
been updated. Restored original structure with tj-actions/changed-files
and mheap/github-action-required-labels actions, only updating filename
from mx_platform_api.yml to v20111101.yaml.

Author: Nicki Nixon

.github/workflows/version.yml

@@ -16,10 +16,14 @@ jobs:
         id: changed-files-specific
         uses: tj-actions/changed-files@v41
         with:
-          files: openapi/v20111101.yml
+          files: openapi/v20111101.yaml
 
-      - name: Require version label on OpenAPI change
-        if: contains(github.event.pull_request.labels.*.name, 'needs version')
-        run: |
-          files=$(git diff --name-only origin/master...HEAD)
-          if echo "$files" | grep -q "openapi/v20111101.yaml"; then
+      - name: Require version label if openapi spec changed
+        if: steps.changed-files-specific.outputs.any_changed == 'true'
+        uses: mheap/github-action-required-labels@v4
+        with:
+          mode: exactly
+          count: 1
+          labels: "major, minor, patch"
+          add_comment: true
+          message: "This PR is blocked until you add one of the following labels: {{ provided }}. Once added you can merge."