infra: improve check-links CI job

.github/workflows/check-links.yml

@@ -3,45 +3,45 @@ on:
   push:
     branches: [ main ]
   pull_request:
+    paths:
+      - '**/*.md'
+      - '.github/workflows/check-links.yml'
+      - '.github/workflows/check_links_config.json'
 
 permissions:
   contents: read
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
-  changedfiles:
-    name: changed files
-    runs-on: ubuntu-latest
-    if: ${{ github.actor != 'dependabot[bot]' }}
-    outputs:
-      md: ${{ steps.changes.outputs.md }}
-    steps:
-      - name: Checkout Repo
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - name: Get changed files
-        id: changes
-        run: |
-          echo "md=$(git diff --name-only --diff-filter=ACMRTUXB $(git merge-base origin/main ${{ github.event.pull_request.head.sha }}) ${{ github.event.pull_request.head.sha }} | grep .md$ | xargs)" >> $GITHUB_OUTPUT
   check-links:
     runs-on: ubuntu-latest
-    needs: changedfiles
-    if: |
-      github.event.pull_request.user.login != 'otelbot[bot]' && github.event_name == 'pull_request'
-      && ${{needs.changedfiles.outputs.md}}
+    timeout-minutes: 15
+    if: ${{ github.actor != 'dependabot[bot]' && github.actor != 'otelbot[bot]' }}
     steps:
       - name: Checkout Repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
+      - name: Get changed markdown files
+        id: changed-files
+        uses: tj-actions/changed-files@v46
+        with:
+          files: |
+            **/*.md
+
       - name: Install markdown-link-check
+        if: steps.changed-files.outputs.any_changed == 'true'
         run: npm install -g markdown-link-check@v3.12.2
 
       - name: Run markdown-link-check
+        if: steps.changed-files.outputs.any_changed == 'true'
         run: |
           markdown-link-check \
             --verbose \
             --config .github/workflows/check_links_config.json \
-            ${{needs.changedfiles.outputs.md}} \
+            ${{ steps.changed-files.outputs.all_changed_files }} \
             || { echo "Check that anchor links are lowercase"; exit 1; }

CHANGELOG.md

@@ -22,6 +22,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#4935](https://github.com/open-telemetry/opentelemetry-python/pull/4935))
 - `opentelemetry-sdk`: upgrade vendored OTel configuration schema from v1.0.0-rc.3 to v1.0.0
   ([#4965](https://github.com/open-telemetry/opentelemetry-python/pull/4965))
+- improve check-links ci job
+  ([#4965](https://github.com/open-telemetry/opentelemetry-python/pull/4965))
 
 ## Version 1.40.0/0.61b0 (2026-03-04)