Action unit test and process test versions updated

[PennyHow]

This was raised by @BaptisteVandecrux in his latest PR #207 where the unit test was not working due to the pkg_resources package not being recognised.

I discovered the problem was with the Github Action itself - we are using an old version of the checkout and setup-python Actions, which have just been deprecated. So I have updated these in this PR.

In addition, to make sure we don't have problems from this again, I have hard coded for the setuptools package to be upgraded during the Python setup step in each Action. This should mean that the pkg_resources package will be found for running the unit test and process test.

After this PR is merged with the main branch, then you should be able to run the Actions on your PR @BaptisteVandecrux. Then you should be able to continue with merging.

[BaptisteVandecrux]

Thanks Penny!

My only comment is that you use checkout@v3 when they have released a checkout@v4: https://github.com/actions/checkout
I guess it doesn't matter right now but it is annoying that they deprecate things that fast.
checkout@v2's last release was May 30 this year!

[PennyHow]

My only comment is that you use checkout@v3 when they have released a checkout@v4: https://github.com/actions/checkout I guess it doesn't matter right now but it is annoying that they deprecate things that fast. checkout@v2's last release was May 30 this year!

I thought about this, but chose checkout@v3 because all examples use the specific combination of checkout@v3 and setup-python@v4. I think we can update it in the future when they begin pushing for v4 in their examples though.