build: Require aiohttp v3.9.0+

[matthewfeickert]

What does this PR do?

• Provide a lower bound of v3.9.0 for aiohttp. (c.f. New Release #785 (comment)).
• v3.9.0 was validated in PR Bump aiohttp from 3.9.0b0 to 3.9.0 #760

[codecov]

Codecov Report

Merging #789 (be2cf75) into main (cb2eb37) will decrease coverage by 0.26%.
Report is 7 commits behind head on main.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #789      +/-   ##
==========================================
- Coverage   91.54%   91.29%   -0.26%     
==========================================
  Files          17       17              
  Lines        1621     1631      +10     
==========================================
+ Hits         1484     1489       +5     
- Misses        137      142       +5     

[matthewfeickert]

For whatever reason Codedcov is failing coverage, while it is passing on main, but that is safe to ignore as this is a 1-line diff.

[matthewfeickert]

Thanks for the fast review and merge, @MSeal!