[rb-general] Addresses in (I)Python output

[Rebecca N. Palmer]

I agree that we don't want to disable IPython address output during 
interactive use.  Options:

- jupyter-nbconvert may well be a suitable "documentation builds go 
through here, interactive use doesn't" place to disable address output 
by default (either by passing a "disable address output" command-line 
switch to IPython or by a search-and-replace on the output), but I need 
to check that.

- or, do we have a standard "is a reproducible build currently being 
attempted?" mechanism, that IPython could use to decide whether to 
disable address output?  (Checking whether SOURCE_DATE_EPOCH is set?)

- or, we could put a "remove Python addresses" post-processor in 
strip-nondeterminism.