Update dependabot config (#875)

Author: benmccann

.github/dependabot.yml

@@ -1,19 +1,20 @@
 # For all possible configuration options see:
 # https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
 
+# Note that limitations on version updates applied in this file don't apply to security updates,
+# which are separately managed by dependabot
+
 version: 2
 updates:
   - package-ecosystem: "npm"
     directory: "/"
     schedule:
       interval: "daily"
-    # Allow up to 10 open pull requests for dependencies.
-    open-pull-requests-limit: 5
-  - package-ecosystem: github-actions
-    directory: /
-    groups:
-      github-actions:
-        patterns:
-          - "*"  # Group all Actions updates into a single larger pull request
+    open-pull-requests-limit: 20
+    ignore:
+      - dependency-name: "*"
+        update-types: ["version-update:semver-minor", "version-update:semver-patch"]
+  - package-ecosystem: "github-actions"
+    directory: "/"
     schedule:
-      interval: weekly
+      interval: "daily"