Replace deprecated imp module with importlib

[hugovk]

This project, via vendored boto, uses the imp module which has been deprecated since Python 3.4 and removed in 3.12:

• Raised PendingDeprecationWarning since 3.4 (2014)
• Raised DeprecationWarning since 3.5 (2015)
• Updated DeprecationWarning to say removal in 3.12 since 3.10 (2021)
• Removal planned for 3.12 (2023)

Python 3.12 is set for release on 2023-10-02 and this library is one of the top 5,000 most-downloaded from PyPI.

Please could you upgrade to use importlib? The imp docs have suggestions on what to use to replace each function and constant.

[thomasmaclean]

I made an attempt at resolving this here, as imp wasn't used particularly frequently in boto:

https://github.com/gsutil-mirrors/boto/pull/21/files

[hugovk]

https://github.com/mtth/hdfs/pull/192 has been merged, I think this can be closed now.