[FLINK-38329][GithubAction] Change colour of target release label for back port PRs

Signed-off-by: davidradl <[email protected]>

Author: davidradl

.github/workflows/community-review.sh

@@ -425,7 +425,7 @@ ensure_label_exists() {
   local token="${1?missing token}"
   local label_name="${2?missing label name}"
 
-  local color="90EE90"
+  local color="5d069e"
 
   # Check if the label exists
   local label_exists=$(curl --fail --no-progress-meter -s \