Sketcher: Fix dangling command context on double-click text edit

Remove the openCommand() call in editDoubleClicked() since
EditTextDialog already manages its own command lifecycle. The redundant
outer command was never closed when the user cancelled the dialog.

src/Mod/Sketcher/Gui/ViewProviderSketch.cpp

@@ -1352,7 +1352,6 @@ void ViewProviderSketch::editDoubleClicked()
         }
 
         if (textConstrId != -1) {
-            Gui::Command::openCommand(QT_TRANSLATE_NOOP("Command", "Modify Text constraint"));
             EditTextDialog editTextDialog(this, textConstrId);
             editTextDialog.exec();
             setSketchMode(STATUS_NONE);