[WPE] Unreviewed unified-builds build fix

https://bugs.webkit.org/show_bug.cgi?id=248935

Unreviewed, adding a missing header to the WebInspectorUI implementation file
to avoid incomplete-class build errors when the unified builds system shuffles
that file into a different set.

* Source/WebKit/WebProcess/Inspector/WebInspectorUI.cpp:

Canonical link: https://commits.webkit.org/257547@main

Author: zdobersek

Source/WebKit/WebProcess/Inspector/WebInspectorUI.cpp

@@ -35,6 +35,7 @@
 #include <WebCore/Chrome.h>
 #include <WebCore/DOMWrapperWorld.h>
 #include <WebCore/DeprecatedGlobalSettings.h>
+#include <WebCore/ExceptionDetails.h>
 #include <WebCore/FloatRect.h>
 #include <WebCore/InspectorController.h>
 #include <WebCore/InspectorFrontendHost.h>