[15.0][IMP] stock_packaging_calculator: black, isort, prettier

[bosd]

Fixes:

[pedrobaeza]

This is not correct, as it's by design to put a non breakable space.

[bosd]

Previously flake8 and autoflake was broken on 15.0 branch.
After version bump of those modules it generated this error.

This is not correct, as it's by design to put a non breakable space.

Is a update of flake8 rules needed to exclude this E321?

Let's track it in: OCA/oca-addons-repo-template#243

[bosd]

Mentioned error is generated locally by
pre-commit run -a -v

When invoking
pre-commit run -v
The error is not shwowing. It is ok on CI here as well.
So closing this one.