Sounds fine, they're both immutable which helps.
qwop
UTF-8 is an encoding for unicode, that means it's a way of representing a unicode string as actual bytes on a computer.
It is variable length and works by using the first bits of each byte to indicate how many bytes are are needed to represent the current character.
Python also uses an encoding, as you describe in the article, but it's different to UTF-8. Unlike unicode, all characters in Python's representation of the unicode string use the same number of bytes, which is the maximum that any individual unicode character in the string needs.
I'd probably mess up a more detailed explanation of UTF-8 or Python's representation, so I'll let you look into how they work in more detail if you're interested.
It's described in PEP 585, https://peps.python.org/pep-0585/#parameters-to-generics-are-available-at-runtime
It probably really depends on the project, though I'd probably try and start with the tests that are easiest/nicest to write and those which will be most useful. Look for complex logic that is also quite self-contained.
That will probably help to convince others of the value of tests if they aren't onboard already.
The full changelog for this release is here https://docs.python.org/release/3.11.7/whatsnew/changelog.html#python-3-11-7-final
Surprisingly not shown that obviously in the release announcements, but I guess that's fair since most of the changes will have no effect on 99.9999% of people.