use dependabot grouped updates

ignore upload/download-artifact until slsa updates

.github/dependabot.yml

@@ -1,9 +1,24 @@
 version: 2
 updates:
-- package-ecosystem: "github-actions"
-  directory: "/"
-  schedule:
-    interval: "monthly"
-    day: "monday"
-    time: "16:00"
-    timezone: "UTC"
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: monthly
+    ignore:
+      # slsa depends on upload/download v3
+      - dependency-name: actions/upload-artifact
+        versions: '>= 4'
+      - dependency-name: actions/download-artifact
+        versions: '>= 4'
+    groups:
+      github-actions:
+        patterns:
+          - '*'
+  - package-ecosystem: pip
+    directory: /requirements/
+    schedule:
+      interval: monthly
+    groups:
+      python-requirements:
+        patterns:
+          - '*'