WebKit switched to workspace builds by default upstream in c67ee46115 and Playwright.app project (forked from MiniBrowser.app xcode project) was not a part of the workspace. This PR:
* Adds Tools/Playwright project to the WebKit workspace;
* Adds WebKit.framework to the list of dependencies of Playwright.app (I managed to successfully build without this modification but decided to added to be on the safe side as that was done upstream too);
* Removes `--no-use-workspace` in order to use workspace build mode which is the default upstream.
Pretty-diff: 75f1e79447