Change development recommended pyenv python version to a supported version (pandas-dev#45531)

Co-authored-by: AlonMenczer <[email protected]>

Author: 2 people

doc/source/development/contributing_environment.rst

@@ -222,7 +222,7 @@ Consult the docs for setting up pyenv `here <https://github.com/pyenv/pyenv>`__.
    pyenv virtualenv <version> <name-to-give-it>
 
    # For instance:
-   pyenv virtualenv 3.7.6 pandas-dev
+   pyenv virtualenv 3.9.10 pandas-dev
 
    # Activate the virtualenv
    pyenv activate pandas-dev