Update Python to 3.10 on Humble and Rolling

[sloretz]

Matches version on Jammy

https://packages.ubuntu.com/jammy/python3

Alternative to #16

ros-infrastructure/rep#349

Requires #43

[clalancette]

I'm all for this, though I do think we want to switch CI over to using this before we go ahead with this and the connected PRs. Can you open a corresponding PR to https://github.com/ros2/ci, and run CI with it (including Windows Debug)?

[sloretz]

Started CI: ros2/ci#660 (comment)

[audrow]

Looks good to me, but we should wait on ros2/ci#660 (comment) before merging, correct?

[sloretz]

I may need to be back to my Windows machine to get further. I think this answer on SO describes the problem.

PyQt5 is failing to install on Windows because the release of 5.15.0 on PyPI doesn't have binaries for Python 3.10. Pip tries to build it from source, but seems to raise an exception that qmake isn't found. I tried moving the install step of Qt5 above pip installs, but that didn't seem to make qmake available to pip. I'm currently trying PyQt5 5.15.6 because that version uses cPython's stable abi, so maybe it will work with Python 3.10.