Test against Python 3.9

[brettcannon]

No description provided.

[ericsnowcurrently]

LGTM

[IanMatthewHuff]

@brettcannon will this include the Data Science functional tests? I don't believe that we can do that update yet, as there are still 3.9 ipykernel support issues like this one https://app.zenhub.com/workspaces/vscode-python-5a1de248bb238e1c6364bb56/issues/microsoft/vscode-python/14274.

[brettcannon]

@IanMatthewHuff yes it would.

I have converted this back to draft. Please ping this PR once you are ready for 3.9 (which was released this week FYI).

[codecov-io]

Codecov Report

Merging #14303 into main will decrease coverage by 1.24%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #14303      +/-   ##
==========================================
- Coverage   59.91%   58.67%   -1.25%     
==========================================
  Files         709      717       +8     
  Lines       39334    42545    +3211     
  Branches     5698     6532     +834     
==========================================
+ Hits        23567    24963    +1396     
- Misses      14529    16247    +1718     
- Partials     1238     1335      +97     

Impacted Files	Coverage Δ
...c/client/pythonEnvironments/common/windowsUtils.ts	20.68% <0.00%> (-79.32%)	⬇️
...nt/datascience/notebookStorage/vscNotebookModel.ts	39.49% <0.00%> (-18.40%)	⬇️
src/client/datascience/notebook/contentProvider.ts	44.00% <0.00%> (-7.17%)	⬇️
...ascience/jupyter/liveshare/hostJupyterExecution.ts	52.38% <0.00%> (-5.60%)	⬇️
src/client/datascience/common.ts	55.33% <0.00%> (-4.91%)	⬇️
...atascience/notebookStorage/nativeEditorProvider.ts	14.21% <0.00%> (-3.06%)	⬇️
src/client/common/application/notebook.ts	8.04% <0.00%> (-2.87%)	⬇️
src/client/datascience/commands/exportCommands.ts	13.00% <0.00%> (-2.16%)	⬇️
src/client/datascience/export/exportUtil.ts	11.59% <0.00%> (-1.97%)	⬇️
...ascience/jupyter/liveshare/guestJupyterNotebook.ts	7.51% <0.00%> (-1.78%)	⬇️
... and 50 more

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[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
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[IanMatthewHuff]

Thanks for waiting. Should be good now.