MNT: Update GitHub/Dependabot config

Author: effigies

.github/dependabot.yml

@@ -0,0 +1,10 @@
+# Set update schedule for GitHub Actions
+
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every week
+      interval: "weekly"

.github/workflows/pythonpackage.yml

@@ -37,7 +37,7 @@ jobs:
             COMMIT_MSG=$(git show -s --format=%s)
           fi
           echo $COMMIT_MSG
-          echo "::set-output name=commit_message::$COMMIT_MSG"
+          echo "commit_message=$COMMIT_MSG" >> $GITHUB_OUTPUT
         env:
           COMMIT_MSG: ${{ github.event.head_commit.message }}