FileManager: Remove unused PropertyValuePair struct

Author: https://github.com/AtkinsSJ
Commit: a847bd463a
Pull-request: https://github.com/SerenityOS/serenity/pull/19691
Reviewed-by: https://github.com/LucasChollet
Reviewed-by: https://github.com/kleinesfilmroellchen ✅
Reviewed-by: https://github.com/nico ✅

Userland/Applications/FileManager/PropertiesWindow.h

@@ -29,12 +29,6 @@ private:
     PropertiesWindow(DeprecatedString const& path, Window* parent = nullptr);
     ErrorOr<void> create_widgets(bool disable_rename);
 
-    struct PropertyValuePair {
-        DeprecatedString property;
-        DeprecatedString value;
-        Optional<URL> link = {};
-    };
-
     struct PermissionMasks {
         mode_t read;
         mode_t write;