Drop support for EOL Python 3.9

[hugovk]

First pass for #841.

There's some 3.9 still left in https://github.com/hugovk/python-build-standalone/blob/main/cpython-unix/targets.yml because seven targets only support 3.9, like aarch64-apple-ios and arm64-apple-tvos:

https://github.com/hugovk/python-build-standalone/blob/2181bddcc918f14275232ad6d1365035f2ae75c4/cpython-unix/targets.yml#L114-L119

Should they be removed? Or upgraded?

Also ran ruff check --select UP --target-version py310 --fix and run check --fix. There's a lot of --unsafe-fixes that can be applied, but they can be in their own PR to avoid making this too big.

[jjhelmus]

This looks great. Thanks @hugovk

Should they be removed? Or upgraded?

I would suggest removing these targets. They have not been built in CI for a long while and AFAIK have never been released.

[hugovk]

I had removed iOS/tvOS/watchOS stuff from patch files such as

python-build-standalone/cpython-unix/patch-apple-cross.patch

Lines 9 to 17 in bdabbfb

	+ *-apple-ios*)
	+ ac_sys_system=iOS
	+ ;;
	+ *-apple-tvos*)
	+ ac_sys_system=tvOS
	+ ;;
	+ *-apple-watchos*)
	+ ac_sys_system=watchOS
	+ ;;

but they didn't apply so need doing with more care. So I left it out from this already big PR, they can be dealt with another time.