Add max-age Cache-Control header to kernel logos

[divyansshhh]

Issue: #702

[welcome]

Thanks for submitting your first pull request! You are awesome! 🤗

If you haven't done so already, check out Jupyter's Code of Conduct. Also, please make sure you followed the pull request template, as this will help us review your contribution more quickly.

You can meet the other Jovyans by joining our Discourse forum. There is also a intro thread there where you can stop by and say Hi! 👋

Welcome to the Jupyter community! 🎉

[divyansshhh]

Lighthouse no longer complains about the TTL:

[codecov-commenter]

Codecov Report

Merging #760 (69b11f7) into main (e0c126f) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #760      +/-   ##
==========================================
- Coverage   70.80%   70.79%   -0.02%     
==========================================
  Files          62       62              
  Lines        7627     7631       +4     
  Branches     1220     1222       +2     
==========================================
+ Hits         5400     5402       +2     
- Misses       1850     1851       +1     
- Partials      377      378       +1     

Impacted Files	Coverage Δ
jupyter_server/kernelspecs/handlers.py	88.88% <0.00%> (-7.12%)	⬇️
jupyter_server/serverapp.py	65.42% <0.00%> (+0.06%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e0c126f...69b11f7. Read the comment docs.

[Zsailer]

This looks like a reasonable fix to me, based on discussion in #702

[welcome]

Congrats on your first merged pull request in this project! 🎉

Thank you for contributing, we are very proud of you! ❤️