eclipse-temurin: add Stewart Addison as a maintainer

@sxa has been a long-term contributor to the Eclipse Temurin project and is the defacto infra-lead

library/eclipse-temurin

@@ -1,6 +1,7 @@
 # Eclipse Temurin OpenJDK images provided by the Eclipse Foundation.
 
-Maintainers: George Adams <[email protected]> (@gdams)
+Maintainers: George Adams <[email protected]> (@gdams),
+             Stewart Addison <[email protected]> (@sxa)
 GitRepo: https://github.com/adoptium/containers.git
 GitFetch: refs/heads/main