Fix double borrow in synchronous tests that take AppContext

Co-authored-by: Mikayla <mikayla@zed.dev>
Co-authored-by: Antonio <antonio@zed.dev>

crates/gpui2_macros/src/test.rs

@@ -175,6 +175,7 @@ pub fn test(args: TokenStream, function: TokenStream) -> TokenStream {
                                 inner_fn_args.extend(quote!(&mut #cx_varname_lock,));
                                 cx_teardowns.extend(quote!(
                                     #cx_varname_lock.quit();
+                                    drop(#cx_varname_lock);
                                     dispatcher.run_until_parked();
                                 ));
                                 continue;