Check if the HOMEDIR, STMP, and PTMP are writable at setup time

[DavidHuber-NOAA]

What new functionality do you need?

When setting up an experiment, in particular at setup_xml.py time, a check should be added to verify that the user running the experiment is able to write to those directories. This will save debugging time if a user forgets/doesn't know to change these directories.

What are the requirements for the new functionality?

setup_xml.py will fail if it is not possible to create/write to HOMEDIR, STMP, or PTMP. Bonus points if other read directories are also checked (such as rstprod directories).

Acceptance Criteria

• setup_xml.py runs without error when HOMEDIR, STMP, and PTMP are writable
• setup_xml.py raises an error if these directories are not writeable
• A test is written and incorporated into CI testing to verify this feature works

Suggest a solution (optional)

No response

[DavidHuber-NOAA]

FYI @wx20jjung