Update Release Managers description

To be precise, Release Managers to not tag releases or build packages
for Kubernetes. They mainly oversee the process and use the tools we
provide in SIG Release.

Signed-off-by: Sascha Grunert <[email protected]>

Author: saschagrunert

content/en/releases/release-managers.md

@@ -4,8 +4,8 @@ type: docs
 ---
 
 "Release Managers" is an umbrella term that encompasses the set of Kubernetes
-contributors responsible for maintaining release branches, tagging releases,
-and building/packaging Kubernetes.
+contributors responsible for maintaining release branches and creating releases
+by using the tools SIG Release provides.
 
 The responsibilities of each role are described below.