Bump io.github.ascopes:protobuf-maven-plugin from 2.7.3 to 2.9.1

Bumps [io.github.ascopes:protobuf-maven-plugin](https://github.com/ascopes/protobuf-maven-plugin) from 2.7.3 to 2.9.1.
- [Release notes](https://github.com/ascopes/protobuf-maven-plugin/releases)
- [Commits](ascopes/protobuf-maven-plugin@v2.7.3...v2.9.1)

---
updated-dependencies:
- dependency-name: io.github.ascopes:protobuf-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

pom.xml

@@ -181,7 +181,7 @@
         <plugin>
           <groupId>io.github.ascopes</groupId>
           <artifactId>protobuf-maven-plugin</artifactId>
-          <version>2.7.3</version>
+          <version>2.9.1</version>
           <configuration>
             <protocVersion>${protobuf.version}</protocVersion>
           </configuration>