[CI][NITPICK] .yml to yaml github workflows (#9664)

# Introduction
Applying the most present `yaml` file extension to all
`.github/workflows/` files

## Notes
Regarding the `restore-cache` and `save-cache` composite actions github
agnostically searches for any `DockerFile` `action.yml` and
`action.yaml` within the target folder when invoking composite actions
as follows:
```yml
      - name: Restore storybook build cache
        if: steps.changed-files.outputs.any_changed == 'true'
        uses: ./.github/workflows/actions/restore-cache
        with: 
          key: ${{ env.STORYBOOK_BUILD_CACHE_KEY }}
```

.github/workflows/actions/save-cache/action.yaml

@@ -0,0 +1,21 @@
+name: Save cache
+inputs:
+  key:
+    required: true
+    description: Primary key to the cache, should be retrieved from `cache-restore` composite action outputs.
+  additional-paths:
+    required: false
+
+runs:
+  using: "composite"
+  steps:
+    - name: Save cache
+      uses: actions/cache/save@v4
+      with:
+        key: ${{ inputs.key }}
+        path: |
+          .cache
+          .nx/cache
+          node_modules/.cache
+          packages/*/node_modules/.cache
+          ${{ inputs.additional-paths }}