chore(deps): update actions/checkout action to v4

.github/workflows/changed-files.yml

@@ -52,7 +52,7 @@ jobs:
     outputs:
       changed_dirs: ${{ steps.changed-files.outputs.all_changed_files }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0  # OR "2" -> To retrieve the preceding commit.
 
@@ -83,7 +83,7 @@ jobs:
     needs:
       - get-changed-dirs
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: "do sth on changed dir ${{ matrix.dir }}"
         run: |
           echo "do sth on changed dir ${{ matrix.dir }}" >> "$GITHUB_STEP_SUMMARY"