chore: update beekeeper branch to bee-playground

Author: gacevicljubisa

.github/workflows/beekeeper.yml

@@ -19,7 +19,7 @@ env:
   SETUP_CONTRACT_IMAGE: "ethersphere/bee-localchain"
   SETUP_CONTRACT_IMAGE_TAG: "0.9.4"
   BEELOCAL_BRANCH: "main"
-  BEEKEEPER_BRANCH: "master"
+  BEEKEEPER_BRANCH: "bee-playground"
   BEEKEEPER_METRICS_ENABLED: false
   REACHABILITY_OVERRIDE_PUBLIC: true
   BATCHFACTOR_OVERRIDE_PUBLIC: 2