chore: remove staging bucket v2 (#291)

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Source-Link: googleapis/synthtool@572ef8f

.kokoro/release/publish_javadoc.sh

@@ -24,11 +24,6 @@ if [[ -z "${STAGING_BUCKET}" ]]; then
   exit 1
 fi
 
-if [[ -z "${STAGING_BUCKET_V2}" ]]; then
-  echo "Need to set STAGING_BUCKET_V2 environment variable"
-  exit 1
-fi
-
 # work from the git root directory
 pushd $(dirname "$0")/../../
 

synth.metadata

@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "bb854b6c048619e3be4e8b8ce8ed10aa74ea78ef"
+        "sha": "572ef8f70edd9041f5bcfa71511aed6aecfc2098"
       }
     }
   ],