Remove creation of release tag (#4988)

The release tag is now created alongside the GitHub release.

buildspecs/release-to-github.yml

@@ -18,15 +18,5 @@ phases:
     - cd release
     -
     - git clone -o staging -b release $STAGING_REPOSITORY_URL .
-    - RELEASE_VERSION=`mvn -q -Dexec.executable=echo -Dexec.args='${project.version}' --non-recursive exec:exec`
-    -
     - git remote add --fetch public $PUBLIC_REPOSITORY_URL
-    - |
-      if [ `git ls-remote --tags public  | grep refs/tags/$RELEASE_VERSION | wc -l` -ge "1" ]; then
-        git push public :refs/tags/$RELEASE_VERSION
-        git tag --delete $RELEASE_VERSION
-      fi
-    - git tag -a $RELEASE_VERSION -m "AWS SDK for Java v2 ($RELEASE_VERSION)"
-    -
     - git push public HEAD:release
-    - git push public $RELEASE_VERSION