ENH: Update actions/checkout to version4

Keep in sync with the other remote modules.

Author: hjmjohnson

.github/workflows/apply-clang-format.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v4
     - uses: InsightSoftwareConsortium/ITKApplyClangFormatAction@master
       with:
         github-token: ${{ secrets.GITHUB_TOKEN }}