ProjectExplorer: Make CodeStyleSettingsWidget expanding

This encourages the code style project settings panel to take the
abundant vertical space.

Change-Id: Ia14c4e3246a0ab4099850b3013e4ea915a7e1433
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/projectexplorer/codestylesettingspropertiespage.cpp

@@ -35,6 +35,7 @@ public:
 
         setGlobalSettingsId(CppEditor::Constants::CPP_CODE_STYLE_SETTINGS_ID);
         setUseGlobalSettingsCheckBoxVisible(false);
+        setExpanding(true);
 
         const EditorConfiguration *config = project->editorConfiguration();