Update maintainers for GBP release team

Author: nbbrooks

package.xml

@@ -6,8 +6,10 @@
   <description>ROS Support Library</description>
   <author email="maybe@tylerjw.dev">Tyler Weaver</author>
   <author email="chrisjthrasher@gmail.com">Chris Thrasher</author>
-  <maintainer email="maybe@tylerjw.dev">Tyler Weaver</maintainer>
-  <maintainer email="chrisjthrasher@gmail.com">Chris Thrasher</maintainer>
+  <maintainer email="bence.magyar.robotics@gmail.com">bmagyar</maintainer>
+  <maintainer email="christoph.froehlich@ait.ac.at">christophfroehlich</maintainer>
+  <maintainer email="nathanbrooks@picknik.ai">Nathan Brooks</maintainer>
+  <maintainer email="shaurya.kumar@picknik.ai">Shaurya Kumar</maintainer>
   <license>BSD-3-Clause</license>
 
   <buildtool_depend>doxygen</buildtool_depend>