Update checkout action to v5

Author: stuarthayhurst

.github/workflows/build-extension.yml

@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - name: Install build dependencies
       run: |
         sudo apt-get update

.github/workflows/shellcheck.yml

@@ -10,7 +10,7 @@ jobs:
   shellcheck:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Run shellcheck
         run: |
           find $GITHUB_WORKSPACE -type f -and \( -name "*.sh" \) | xargs shellcheck

.github/workflows/test-build-system.yml

@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - name: Install build dependencies
       run: |
         sudo apt-get update