Going back to v4 because it did not seem to help to go back down to v3

.github/workflows/testsuite.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: perl -V
         run: perl -V
       - name: Install perl-doc
@@ -69,7 +69,7 @@ jobs:
       image: perl:${{ matrix.perl-version }}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Show Perl version
         run: perl -V
       - name: Install dependencies
@@ -92,7 +92,7 @@ jobs:
       PERL_CARTON_PATH: $GITHUB_WORKSPACE/local
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Perl
         run: brew install perl
       - name: perl -V
@@ -111,7 +111,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Perl
         run: |
           choco install strawberryperl