Disable Clear-Site-Data HTTP header support at runtime until I get a chance to update the implementation to respect origin partitioning.
Pull request: https://github.com/WebKit/WebKit/pull/6309
Committed 256513@main (17c0b7153c2f): <https://commits.webkit.org/256513@main> Reviewed commits have been landed. Closing PR #6309 and removing active labels.
<rdar://problem/102169567>