Merge pull request #3002 from effigies/deps/dependabot-config

chore(deps): Configure dependabot to group PRs and update GHA

.github/dependabot.yml

@@ -0,0 +1,18 @@
+version: 2
+updates:
+  - package-ecosystem: 'github-actions'
+    directory: '/'
+    schedule:
+      interval: 'monthly'
+    groups:
+      actions-infrastructure:
+        patterns:
+          - 'actions/*'
+  - package-ecosystem: 'pipenv'
+    directory: '/services/datalad'
+    schedule:
+      interval: 'monthly'
+    groups:
+      pipenv:
+        patterns:
+          - '*'