build(ci): Bump pr-labels-action to use node20 (#10416)

I also opened a PR upstream:
joerick/pr-labels-action#17 but merging speed is
rather slow there, so I'd rather not wait for this.

Author: mydea

.github/workflows/build.yml

@@ -136,7 +136,7 @@ jobs:
 
       - name: Get PR labels
         id: pr-labels
-        uses: mydea/pr-labels-action@update-core
+        uses: mydea/pr-labels-action@fn/bump-node20
 
     outputs:
       commit_label: '${{ env.COMMIT_SHA }}: ${{ env.COMMIT_MESSAGE }}'