fix: type annotation breaking on py3.9

[dpgaspar]

SUMMARY

A recent change as broke Superset on python 3.9. To my understanding we still support python 3.9 as per https://github.com/apache/superset/blob/master/pyproject.toml#L27

I do think we should run our tests on the minimal python version as well to avoid these issues, but I'm not sure on how to change it on github actions, or we don't set it or we use python-version: ["current", "next"]

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TESTING INSTRUCTIONS

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[michael-s-molina]

Thanks for the fix @dpgaspar!

I do think we should run our tests on the minimal python version as well to avoid these issues, but I'm not sure on how to change it on github actions, or we don't set it or we use python-version: ["current", "next"]

That's a fair point. I didn't even notice that we were missing the from __future__ import annotations because neither the tests or pre-commit hook complained about it. I believe we'll have many more of these problems if these checks don't catch these types of errors.

@mistercrunch Is it possible to fix this?

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.13%. Comparing base (2e5f3ed) to head (826f6de).
Report is 58 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #28396       +/-   ##
===========================================
+ Coverage   60.49%   83.13%   +22.64%     
===========================================
  Files        1931      521     -1410     
  Lines       76241    37256    -38985     
  Branches     8566        0     -8566     
===========================================
- Hits        46122    30973    -15149     
+ Misses      28015     6283    -21732     
+ Partials     2104        0     -2104     

Flag	Coverage Δ
hive	?
javascript	?
mysql	77.20% <100.00%> (?)
postgres	77.32% <100.00%> (?)
presto	53.66% <100.00%> (-0.14%)	⬇️
python	83.13% <100.00%> (+19.64%)	⬆️
sqlite	76.78% <100.00%> (?)
unit	58.35% <100.00%> (+0.72%)	⬆️

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[mistercrunch]

#28419 should help prevent this