Update workflow - and try to keep actions updated

Author: koppor

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/test.yml

@@ -7,8 +7,8 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - name: Set up Git repository
-        uses: actions/checkout@v1
+      - uses: actions/checkout@v4
+      - uses: gautamkrishnar/keepalive-workflow@v2
       - name: Compile basic LaTeX document
         uses: ./
         with: