Update actions/checkout action to v5

.github/workflows/check-nix-format.yml

@@ -19,7 +19,7 @@ jobs:
     name: nixfmt-check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
         with:
           fetch-depth: 2
       - name: Calculate changed files

.github/workflows/pr.yml

@@ -10,7 +10,7 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+    - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
     - uses: cachix/install-nix-action@17fe5fb4a23ad6cbbe47d6b3f359611ad276644c # v31
       with:
         nix_path: nixpkgs=channel:nixos-unstable

.github/workflows/update.yml

@@ -23,7 +23,7 @@ jobs:
         application_private_key: '${{ secrets.GH_APPLICATION_PRIVATE_KEY }}'
         permissions: "contents:write"
         revoke_token: true
-    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+    - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
     - uses: cachix/install-nix-action@17fe5fb4a23ad6cbbe47d6b3f359611ad276644c # v31
       with:
         nix_path: nixpkgs=channel:nixos-unstable