Add protobuf-team to CODEOWNERS

Adding protobuf team and removing lberki
diff --git a/CODEOWNERS b/CODEOWNERS
index 44976fd..434bee5 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -1 +1 @@
-* @lberki @comius
+* @comius @bazelbuild/protobuf-team