fix: return 404 for non-existing revisions

[maybe-hello-world]

Links to non-existing revisions to docs should return 404
Closes #5934

[codecov]

Codecov Report

Merging #6014 (17fe4d5) into main (09f3477) will decrease coverage by 0.03%.
The diff coverage is 88.88%.

@@            Coverage Diff             @@
##             main    #6014      +/-   ##
==========================================
- Coverage   88.67%   88.64%   -0.03%     
==========================================
  Files         288      288              
  Lines       40001    40010       +9     
==========================================
- Hits        35471    35467       -4     
- Misses       4530     4543      +13     

Impacted Files	Coverage Δ
ietf/doc/views_stats.py	74.80% <ø> (ø)
ietf/ietfauth/widgets.py	84.61% <ø> (ø)
ietf/nomcom/views.py	92.90% <33.33%> (-0.22%)	⬇️
ietf/doc/utils.py	87.15% <100.00%> (+0.01%)	⬆️
ietf/doc/views_doc.py	91.65% <100.00%> (+0.03%)	⬆️
ietf/doc/views_search.py	89.13% <100.00%> (+0.20%)	⬆️
ietf/nomcom/templatetags/nomcom_tags.py	70.83% <100.00%> (+3.64%)	⬆️
ietf/submit/forms.py	79.02% <100.00%> (+0.03%)	⬆️

... and 6 files with indirect coverage changes

[jennifer-richards]

Looks good, but I think one small addition is needed. See inline comment.

[maybe-hello-world]

Feel free to squash before merging to simplify history if needed 😅

[jennifer-richards]

Feel free to squash before merging to simplify history if needed 😅

:-) that's our usual practice, otherwise our history would be more, uh, "interesting."

[jennifer-richards]

Looks good. Your last change, I think, restores the behavior of returning the current bibtex for a request for a (non RFC) draft with a nonexistent revision. That seems fine to me.