Add dependabot.yml for Github Actions updates

And save it some work and update Actions to latest versions.

.github/dependabot.yml

@@ -0,0 +1,10 @@
+version: 2
+# Before applying suggested PRs, make sure that the new versions of any
+# updated actions are allowed in
+# https://github.com/organizations/geany/settings/actions
+# Versions are pinned and restricted for security reasons.
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/linting.yml

@@ -34,10 +34,10 @@ jobs:
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Setup Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python }}
 
@@ -60,7 +60,7 @@ jobs:
     runs-on: ubuntu-22.04
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Install dependencies
         run: |