Partial revert build-test-packages fix (build directory)

Partial revert of [1] as discussed in related-bug this is no longer
necessary after [2] merged.

Related-Bug: 1895138
[1] https://review.opendev.org/#/c/750443/
[2] https://review.opendev.org/#/c/752681/
Change-Id: I27755af71063f03d5f182782c6cc8a2f7475d3a5

playbooks/multinode-standalone-upgrade.yml

@@ -43,8 +43,6 @@
     # durring the upgrade process. For general installation it's ok to have
     # this enabled, but this needs to be disabled for upgrades
     ib_gating_repo_update: false
-    # pass build_repo_dir https://bugs.launchpad.net/tripleo/+bug/1895138
-    build_repo_dir: "/home/{{ undercloud_user }}"
   roles:
     - build-test-packages
     - {role: install-built-repo, when: compressed_gating_repo is defined}