Update actions/checkout action to v5

Author: renovate[bot]

.github/workflows/spm.yml

@@ -11,7 +11,7 @@ jobs:
 
     steps:
       - name: Checkout to the branch
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Install Swift
         uses: slashmo/[email protected]
         with:

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Test
         run: |
           set -ex