Update getting-started.rst about ExceptionGroup.

[kmoonn]

The ExceptionGroup class is only available in Python 3.11 and later versions. If you're using an older version of Python, that's why you're seeing this NameError.

[The-Compiler]

pytest already depends on exceptiongroup on those Python versions:

pytest/pyproject.toml

Line 51 in f373974

"exceptiongroup>=1.0.0rc8; python_version<'3.11'",

So the only reason why you'd get an error there is a broken setup of some sorts. @kmoonn could you elaborate what the motivation for this change is?

[lanzz]

I don't understand the wording of this change. "... that's why you're seeing this NameError" - this implies a NameError that has already been mentioned somewhere, but there's no such earlier mention in getting-started.rst. This looks like a response copied out of context from an issue or an online community?