ci: use "ref_name" instead of "refName" in GH action (#5882)

fix: use `ref_name` instead of `refName`

Signed-off-by: Ilya Lobkov <ilya.lobkov@konghq.com>
(cherry picked from commit d24c433)

.github/workflows/pr-merged.yaml

@@ -27,7 +27,7 @@ jobs:
               pr = context.payload.pull_request.number;
             } else if (context.eventName == "push") {
               const versionRegex = /v?(\d+)\.(\d+)\.\d+/;
-              const versionMatch = context.github.refName.match(versionRegex);
+              const versionMatch = context.github.ref_name.match(versionRegex);
               if (!versionMatch) {
                 return;
               }