ci: update checkout action from v2 to v6

Author: rzmk

.github/workflows/run-ckan-only-install.yml

@@ -10,12 +10,12 @@ on:
 jobs:
   ckanonlyinstall:
     name: Run ckan-devstaller with a CKAN-only install
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     permissions:
       # For the git-auto-commit-action
       contents: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Install Rust stable toolchain
         uses: dtolnay/rust-toolchain@stable
       - name: Cache cargo deps and target folder