Bump guava from 24.1.1-jre to 29.0-jre in /genconvert (google#76)

Bumps [guava](https://github.com/google/guava) from 24.1.1-jre to 29.0-jre.
- [Release notes](https://github.com/google/guava/releases)
- [Commits](https://github.com/google/guava/commits)

Signed-off-by: dependabot[bot] <support@github.com>

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

genconvert/pom.xml

@@ -27,7 +27,7 @@
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>
-      <version>24.1.1-jre</version>
+      <version>29.0-jre</version>
     </dependency>
     <dependency>
       <groupId>junit</groupId>