todo when bump minimum Python version to 3.11

[maread99]

• Try losing remaining from __future__ import annotations lines (if can't lose these lines for any reason then move this point forward for review when bump to 3.12). Currently required in order to:
  • use typing.TYPE_CHECKER to avoid type annotations causing circular imports.
  • use | in a typed return.
  • use classes defined in a module as type annotations elsewhere within that same module.
• Should be able to lose the etc/requirements_dependabot/requirements_tests_upper.txt file and amend the build-test actions workflow as noted in comments there. The reason the requirements_upper file is needed is because the tables module does not provide a wheel for python 3.13 prior to tables version 3.10.2 (and the Windows runner doesn't seem to be able to install it without the wheel). However tables v3.10.2 requires >= python 3.11.... hence the temporary use of separate requirements files for the lower and upper python versions of the text matrix (the only difference with the upper version is that it fixes tables to 3.10.2 whilst the lower one has it fixed to 3.10.1).