Update membership check implementation to avoid PAT requirement (#1427)

See (and is blocked by)
hazelcast/hazelcast-tpm#71

Author: JackPGreen

.github/workflows/build-pr.yml

@@ -46,9 +46,8 @@ jobs:
         id: test-membership
         uses: hazelcast/hazelcast-tpm/membership@main
         with:
-          organization-name: hazelcast
           member-name: ${{ github.actor }}
-          token: ${{ secrets.GH_TOKEN }}
+          token: ${{ github.token }}
 
   # ensure PR is trusted
   ensure-membership: