Fix Windows CI failure in CFKnownLocations - Remove broken username check

Co-authored-by: ShikiSuen <3164826+ShikiSuen@users.noreply.github.com>

Author: Copilot

Sources/CoreFoundation/CFKnownLocations.c

@@ -96,15 +96,7 @@ CFURLRef _Nullable _CFKnownLocationCreatePreferencesURLForUser(CFKnownLocationUs
             break;
         }
         case _kCFKnownLocationUserCurrent:
-            username = CFGetUserName();
-            // The above API returns a non-NULL CFStringRef. The failed result is an empty string.
-            // We need to check for that case and fall through to the next case.
-            Boolean isEmpty = CFEqual(username, CFSTR(""));
-            CFRelease(username);
-            if (!isEmpty) {
-                break;
-            }
-            // fallthrough.
+            // fallthrough
         case _kCFKnownLocationUserByName: {
             wchar_t* path = NULL;
             SHGetKnownFolderPath(&FOLDERID_LocalAppData, 0, NULL, &path);