[Chapel Merge] Avoid chpldoc failures on our Ubuntu boxes

Branch: refs/heads/master
Revision: 102b25e
Author: lydia-duncan
Log Message:

Merge pull request #17928 from lydia-duncan/fixChpldocFailures

Avoid chpldoc failures on our Ubuntu boxes
[reviewed by @Maxrimus]

Adjust nightly to check the Python version instead of if it's a linux32 config.
This is a better predicter of if we can appropriately build chpldoc, since it
seems like all the Ubuntu boxes use this older version

Skips the mason test if the Python version is 3.5 or earlier. In the man page
test, skips checking the chpldoc portion under the same conditions.

I intend to remove all this code when we no longer have machines with Python
3.5, since it seems a little suspect to lock us into a Python version.

Verified that these operate correctly in scenarios where Python 3.5 is not used.

Modified Files:
A test/mason/mason-doc/SKIPIF

R test/mason/mason-doc/SKIPIF
M test/man/checkManPages
M util/cron/nightly

Compare: https://github.com/chapel-lang/chapel/compare/ce57606d19cb...102b25ec9538