gerrit-name -> $ZUUL_PROJECT in macro git-zuul

Zuul provides the Gerrit project name has ZUUL_PROJECT environnement
variable.  Use that directly in the `git-zuul` scm macro.

Jobs updated:

apps-android-commons-build
integration-docroot-jslint
labs-tools-grrrit-jslint
mediawiki-core-jslint
mediawiki-core-phpcs-HEAD
mediawiki-core-phpcs-lenient
mediawiki-core-phpcs-lenient-HEAD
mediawiki-core-phpcs-strict
mediawiki-core-phpcs-strict-HEAD
mediawiki-core-regression-phpcs
mediawiki-core-regression-phpcs-HEAD
mwext-Translate-phpcs-lenient
mwext-Translate-phpcs-lenient-HEAD
mwext-Translate-phpcs-strict
mwext-Translate-phpcs-strict-HEAD
wikimedia-fundraising-tools-jslint

bug: 53470
Change-Id: I51bf7caefd6c22aeddaa4bf4dcb55a142622b21a