Disable building XPC services when launching WebKit processes as extensions.
<rdar://problem/120677588>
Pull request: https://github.com/WebKit/WebKit/pull/22527
Committed 272868@main (c0d19cb34e3a): <https://commits.webkit.org/272868@main> Reviewed commits have been landed. Closing PR #22527 and removing active labels.
Re-opened since this is blocked by bug 267396
Pull request: https://github.com/WebKit/WebKit/pull/22660
Committed 273113@main (a945ee0ce309): <https://commits.webkit.org/273113@main> Reviewed commits have been landed. Closing PR #22660 and removing active labels.