Simplify dependabot: merge maven groups into one (#148)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: infeo <9036915+infeo@users.noreply.github.com>

Author: Copilot

.github/dependabot.yml

@@ -11,22 +11,9 @@ updates:
       - dependency-name: "org.cryptomator:integrations-api"
         versions: [ "2.0.0-alpha1" ]
     groups:
-      java-test-dependencies:
-        patterns:
-          - "org.junit.jupiter:*"
-      maven-build-plugins:
-        patterns:
-          - "org.apache.maven.plugins:*"
-          - "org.owasp:dependency-check-maven"
-          - "org.sonatype.central:central-publishing-maven-plugin"
-      java-production-dependencies:
+      maven-dependencies:
         patterns:
           - "*"
-        exclude-patterns:
-          - "org.junit.jupiter:*"
-          - "org.apache.maven.plugins:*"
-          - "org.owasp:dependency-check-maven"
-          - "org.sonatype.central:central-publishing-maven-plugin"
 
   - package-ecosystem: "github-actions"
     directory: "/" # even for `.github/workflows`