Update documentation/enforcement of minimum supported interpreter version

[d-w-moore]

irods.minimum_compatible_python needs updating to (3, 9).

Also, the thrown RuntimeError is too general. It should be more specific in order to support a user's override e.g. saying "I really have to support this slightly outdated interpreter for the moment." Presently you would have to do this in such a case:

try:
  import irods
except RuntimeError as exc:
  if 'library is only supported on' not in exc.args[0] 
    raise

[korydraughn]

Is this something we have to enforce at the implementation level?

I'd assume pip would report an error on install or upgrade if the interpreter doesn't satisfy the version requirements.

[alanking]

For reference, we're talking about this:

python-irodsclient/irods/__init__.py

Lines 3 to 10 in 2ecc3a3

	minimum_compatible_python = (3, 6)
	if sys.version_info < minimum_compatible_python:
	to_dotted_string = lambda version_tuple: ".".join(str(_) for _ in version_tuple)
	version_message = "This library is only supported on Python {} and above.".format(
	to_dotted_string(minimum_compatible_python)
	)
	raise RuntimeError(version_message)

Because we have >=3.9 requirement here:

python-irodsclient/pyproject.toml

Line 8 in 2ecc3a3

requires-python = ">= 3.9"

I'd assume pip would report an error on install or upgrade if the interpreter doesn't satisfy the version requirements.

Same.