Review if_transient_error docstrings

[daniel-sanche]

Context in this thread

doc: I'm fine with the function-type naming you have, but if Python treats this as a constant, we should make sure the documentation format is appropriate for that so it shows up in IDEs, etc. Is the triple-quoted form the right format for constants' comments? I only recall the hash-prefixed form. It seems triple-quoted strings get assigned to doc when they are "the first statement in a module, function, class, or method definition" (https://peps.python.org/pep-0257/). Elsewhere, they may just get executed (i.e. printed out) when the interpreter encounters that line, which in this case would be on module load.