Bump mavenVersion from 3.9.14 to 3.9.15 (#271)

Bumps `mavenVersion` from 3.9.14 to 3.9.15.

Updates `org.apache.maven:maven-artifact` from 3.9.14 to 3.9.15

Updates `org.apache.maven:maven-core` from 3.9.14 to 3.9.15

Updates `org.apache.maven:maven-model` from 3.9.14 to 3.9.15

Updates `org.apache.maven:maven-plugin-api` from 3.9.14 to 3.9.15
- [Release notes](https://github.com/apache/maven/releases)
- [Commits](apache/maven@maven-3.9.14...maven-3.9.15)

Updates `org.apache.maven:maven-resolver-provider` from 3.9.14 to 3.9.15

---
updated-dependencies:
- dependency-name: org.apache.maven:maven-artifact
  dependency-version: 3.9.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.apache.maven:maven-core
  dependency-version: 3.9.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.apache.maven:maven-model
  dependency-version: 3.9.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.apache.maven:maven-plugin-api
  dependency-version: 3.9.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.apache.maven:maven-resolver-provider
  dependency-version: 3.9.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

maven-plugin-testing-harness/pom.xml

@@ -31,7 +31,7 @@ under the License.
   <description>The Maven Plugin Testing Harness provides mechanisms to manage tests on Mojo.</description>
 
   <properties>
-    <mavenVersion>3.9.14</mavenVersion>
+    <mavenVersion>3.9.15</mavenVersion>
     <resloverVersion>1.9.27</resloverVersion>
     <wagonVersion>3.5.3</wagonVersion>
   </properties>