Bump apache/maven-gh-actions-shared from 3 to 4

Bumps [apache/maven-gh-actions-shared](https://github.com/apache/maven-gh-actions-shared) from 3 to 4.
- [Commits](apache/maven-gh-actions-shared@v3...v4)

---
updated-dependencies:
- dependency-name: apache/maven-gh-actions-shared
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/maven.yml

@@ -22,7 +22,7 @@ on: [push, pull_request]
 jobs:
   build:
     name: Verify
-    uses: apache/maven-gh-actions-shared/.github/workflows/maven-verify.yml@v3
+    uses: apache/maven-gh-actions-shared/.github/workflows/maven-verify.yml@v4
     with:
       ff-maven: "3.9.6"                              # Maven version for fail-fast-build
       maven-matrix: '[ "3.6.3", "3.9.6", "4.0.0-alpha-12" ]'  # Maven versions matrix for verify builds