Fix YW yb_release using the wrong DEVOPS_HOME

Summary:
If DEVOPS_HOME was set, managed/yb_release would use that. This could cause it to point
to an invalid devops repo and break the release. Making sure we reset it to the local in-repo
devops. We are importing ybops pieces inside the managed/yb_release.py.

Test Plan:
call top-level
`yb_release --destination /tmp/tmpjaui3M --force --yw`

Reviewers: wesley, ram, mikhail

Reviewed By: mikhail

Subscribers: jenkins-bot, yugaware

Differential Revision: https://phabricator.dev.yugabyte.com/D7837

managed/yb_release

@@ -2,16 +2,7 @@
 # Copyright (c) YugaByte, Inc.
 set -euo pipefail
 
-# TODO: move this to common file.
-if [[ -z ${DEVOPS_HOME:-} ]]; then
-  devops_home_candidate_dir="${BASH_SOURCE%/*}"/devops
-  if [[ -d $devops_home_candidate_dir ]]; then
-    export DEVOPS_HOME=$( cd "$devops_home_candidate_dir" && pwd )
-  else
-    echo "DEVOPS_HOME not set and the devops repo not found at $devops_home_candidate_dir" >&2
-    exit 1
-  fi
-fi
+export DEVOPS_HOME="${BASH_SOURCE%/*}"/devops
 
 . "$DEVOPS_HOME/bin/"/common.sh