Fix-up pyside6-deploy

Based on feedback from Solution Engineering:

Issue 1:

This tool is probably the most perplexing one for me out of everything I’ve used so I’m the least certain about whether most of the issues I’m about to describe are simply user error or not. The main reason why I’m so unfamiliar with it though is that it’s basically unusable for me since I can’t turn off the --onefile Nuitka option without modifying scripts in the PySide6 library. Security policies at my office will instantly quarantine all --onefile builds as soon as they leave my computer. Although I’m fairly certain that adding a code signing certificate would fix this issue I don’t have the ability to do that at the moment. Furthermore, even if I could sign the binaries, we package our desktop applications into an installer using NSIS either way so that bundling step is pretty unnecessary either way and I would like a supported way to disable it.

Issue 2 (need to be checked):

Now when you run `pyside6-project deploy` I know that the tool generates a pysidedeploy.spec file, but as far as I can tell, it doesn’t get used unless you call the pyside6-deploy tool directly so the project tool’s deploy command seems somewhat useless. This is especially true since the deploy command resets the .spec file and embeds non-portable paths for the icon and python_path fields every time it’s run so it doesn’t make sense to even save the file in source control. Perhaps there’s something I’m missing here, but I couldn’t find any other documented ways of using the command.