[libpas] remove unused variable in ThingyAndUtilityHeapAllocationTests
Pull request: https://github.com/WebKit/WebKit/pull/7820
Committed 258058@main (eee1c52ab0d2): <https://commits.webkit.org/258058@main> Reviewed commits have been landed. Closing PR #7820 and removing active labels.
<rdar://problem/103485939>