dependabot: help keeping GitHub Actions versions up to date (#4792)

See
https://docs.github.com/en/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot#enabling-dependabot-version-updates-for-actions
for details.

.github/dependabot.yml

@@ -0,0 +1,13 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+# especially
+# https://docs.github.com/en/code-security/dependabot/working-with-dependabot/keeping-your-actions-up-to-date-with-dependabot#enabling-dependabot-version-updates-for-actions
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "weekly"

.github/workflows/l10n.yml

@@ -63,7 +63,7 @@ jobs:
             origin \
             ${{ github.ref }} \
             $args
-      - uses: actions/setup-go@v2
+      - uses: actions/setup-go@v5
         with:
           go-version: '>=1.16'
       - name: Install git-po-helper
@@ -91,7 +91,7 @@ jobs:
           cat git-po-helper.out
           exit $exit_code
       - name: Create comment in pull request for report
-        uses: mshick/add-pr-comment@v1
+        uses: mshick/add-pr-comment@v2
         if: >-
           always() &&
           github.event_name == 'pull_request_target' &&