Bump maven-source-plugin from 2.4 to 3.3.0 (#517)

Bumps [maven-source-plugin](https://github.com/apache/maven-source-plugin) from 2.4 to 3.3.0.
- [Commits](apache/maven-source-plugin@maven-source-plugin-2.4...maven-source-plugin-3.3.0)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-source-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

pom.xml

@@ -37,7 +37,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>
-                <version>2.4</version>
+                <version>3.3.0</version>
                 <executions>
                     <execution>
                         <id>attach-sources</id>