Merge pull request #35 from stackhpc/update-actions

CI: Update versions used of community GitHub Actions

Author: markgoddard

.github/workflows/pull_request.yml

@@ -20,7 +20,7 @@ jobs:
           - "2.12"
     steps:
       # Checks-out the repository under $GITHUB_WORKSPACE, so it's accessible to the job
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Install dependencies
         run: |
@@ -50,7 +50,7 @@ jobs:
           - "2.12"
     steps:
       # Checks-out the repository under $GITHUB_WORKSPACE, so it's accessible to the job
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Install dependencies
         run: |