webkit-web-extension.h has been moved to PlatformWPEDeprecated.cmake in 261474@main, but it was not installed the cmake development component anymore.
Pull request: https://github.com/WebKit/WebKit/pull/17124
Committed 267607@main (8dc5dd1ab4c2): <https://commits.webkit.org/267607@main> Reviewed commits have been landed. Closing PR #17124 and removing active labels.