chore(dependabot): configure minor-and-patch grouping (#18)

## Description

Configures Dependabot grouping for minor and patch level updates across
both `maven` dependencies and `github-actions` workflows.

### Changes
- Groups all patch and minor updates under the `minor-and-patch` group
to combine them into single pull requests rather than multiple
individual PRs.
- Major version bumps will continue to be isolated into distinct PRs for
careful review.

## Checklist
- [x] Verified valid YAML syntax and Spotless compliance.

Author: magnusp

.github/dependabot.yml

@@ -7,6 +7,13 @@ updates:
     open-pull-requests-limit: 10
     labels:
       - "dependencies"
+    groups:
+      minor-and-patch:
+        patterns:
+          - "*"
+        update-types:
+          - "minor"
+          - "patch"
 
   - package-ecosystem: "github-actions"
     directory: "/"
@@ -16,3 +23,10 @@ updates:
     labels:
       - "dependencies"
       - "github-actions"
+    groups:
+      minor-and-patch:
+        patterns:
+          - "*"
+        update-types:
+          - "minor"
+          - "patch"