Remove Packaging Dependency

[jtpio]

Packaging should be a build time dependency only.

[codecov-commenter]

Codecov Report

Merging #515 (ef9f319) into master (0c63b2e) will decrease coverage by 0.01%.
The diff coverage is 85.71%.

@@            Coverage Diff             @@
##           master     #515      +/-   ##
==========================================
- Coverage   77.08%   77.06%   -0.02%     
==========================================
  Files         107      107              
  Lines        9495     9500       +5     
  Branches     1027     1029       +2     
==========================================
+ Hits         7319     7321       +2     
- Misses       1807     1808       +1     
- Partials      369      371       +2     

Impacted Files	Coverage Δ
jupyter_server/_version.py	87.50% <85.71%> (-12.50%)	⬇️
jupyter_server/tests/services/kernels/test_api.py	97.05% <0.00%> (-1.97%)	⬇️

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[blink1073]

Thank you!