Downgrade checkout action to v3 for container compatibility

.gitea/workflows/deploy.yaml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3
 
       - name: Install system dependencies
         # Install system dependencies required for R packages (xml2, curl, graphics libraries) + rsync/ssh

.gitea/workflows/lint.yaml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3
 
       - name: Check links
         uses: lycheeverse/lychee-action@v2
@@ -39,7 +39,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3
 
       - name: Install styler
         run: Rscript -e "install.packages('styler')"

.gitea/workflows/test.yaml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v3
 
       - name: Install system dependencies
         run: |