yuzu/CMakeLists: Disable implicit QString->QUrl conversions

Enforces the use of the proper URL resolution functions. e.g.

url = some_local_path_string;

should actually be:

url = QUrl::fromLocalPath(some_local_path_string);

etc.

This makes it harder to cause bugs when operating with both strings and
URLs at the same time.

src/yuzu/CMakeLists.txt

@@ -165,6 +165,9 @@ target_compile_definitions(yuzu PRIVATE
 
     # Disable unsafe overloads of QProcess' start() function.
     -DQT_NO_PROCESS_COMBINED_ARGUMENT_START
+
+    # Disable implicit QString->QUrl conversions to enforce use of proper resolving functions.
+    -DQT_NO_URL_CAST_FROM_STRING
 )
 
 if (YUZU_ENABLE_COMPATIBILITY_REPORTING)