REGRESSION(266606@main): MessageArgumentDescriptions.cpp: Cannot open…

… include file: 'WebExtensionContextIdentifier.h'

https://bugs.webkit.org/show_bug.cgi?id=259839

Windows Debug builds were failing. Unreviewed build fix.

> WebKit\DerivedSources\MessageArgumentDescriptions.cpp(84): fatal error C1083: Cannot open include file: 'WebExtensionContextIdentifier.h': No such file or directory

* Source/WebKit/CMakeLists.txt:
Added an include path to WebKit/Shared/Extensions.

Canonical link: https://commits.webkit.org/266619@main

Source/WebKit/CMakeLists.txt

@@ -40,6 +40,7 @@ set(WebKit_PRIVATE_INCLUDE_DIRECTORIES
     "${WEBKIT_DIR}/Shared/CoreIPCSupport"
     "${WEBKIT_DIR}/Shared/Databases"
     "${WEBKIT_DIR}/Shared/Databases/IndexedDB"
+    "${WEBKIT_DIR}/Shared/Extensions"
     "${WEBKIT_DIR}/Shared/FileAPI"
     "${WEBKIT_DIR}/Shared/Gamepad"
     "${WEBKIT_DIR}/Shared/Notifications"