Avoid duplicate input names in Numba's Scan transpilation

[rlouf]

This PR fixes the issue seen in #1176 when several elements of output_infos are None. The example in the issue now works, but I feel that we are just making up for the underlying issue explained in #1176.

[codecov]

Codecov Report

Merging #1198 (53744c9) into main (cd3a3ce) will not change coverage.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1198   +/-   ##
=======================================
  Coverage   79.14%   79.14%           
=======================================
  Files         173      173           
  Lines       48471    48471           
  Branches    10963    10963           
=======================================
  Hits        38361    38361           
  Misses       7607     7607           
  Partials     2503     2503           

Impacted Files	Coverage Δ
aesara/link/numba/dispatch/scan.py	95.55% <100.00%> (ø)

[rlouf]

I see there's a unique_name_generator function in aesara.link.utils, is that its purpose?

[brandonwillard]

I see there's a unique_name_generator function in aesara.link.utils, is that its purpose?

Yes