Add junit family to avoid pytest warning

[karthiknadig]

For #10673

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR).
• Title summarizes what is changing.
• Has a news entry file (remember to thank yourself!).
• Appropriate comments and documentation strings in the code.
• Has sufficient logging.
• Has telemetry for enhancements.
• Unit tests & system/integration tests are added/updated.
• Test plan is updated as appropriate.
• package-lock.json has been regenerated by running npm install (if dependencies have changed).
• The wiki is updated with any design decisions/details.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
0 Code Smells

No Coverage information
0.0% Duplication

[codecov-io]

Codecov Report

Merging #11748 into master will decrease coverage by 0.08%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master   #11748      +/-   ##
==========================================
- Coverage   60.71%   60.63%   -0.09%     
==========================================
  Files         629      628       -1     
  Lines       33999    33926      -73     
  Branches     4793     4778      -15     
==========================================
- Hits        20643    20570      -73     
- Misses      12350    12358       +8     
+ Partials     1006      998       -8     

Impacted Files	Coverage Δ
src/client/testing/pytest/runner.ts	17.85% <50.00%> (+1.19%)	⬆️
src/datascience-ui/react-common/arePathsSame.ts	75.00% <0.00%> (-12.50%)	⬇️
src/client/common/utils/platform.ts	64.70% <0.00%> (-11.77%)	⬇️
src/client/common/utils/misc.ts	63.63% <0.00%> (-10.73%)	⬇️
src/client/common/installer/productInstaller.ts	86.16% <0.00%> (-6.67%)	⬇️
src/client/logging/transports.ts	77.77% <0.00%> (-3.48%)	⬇️
src/client/common/utils/decorators.ts	78.02% <0.00%> (-2.38%)	⬇️
src/client/linters/pydocstyle.ts	86.66% <0.00%> (-2.23%)	⬇️
src/client/datascience/debugLocationTracker.ts	76.56% <0.00%> (-1.57%)	⬇️
src/client/common/process/proc.ts	14.49% <0.00%> (-0.73%)	⬇️
... and 19 more

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[ericsnowcurrently]

LGTM

[karthiknadig]

Looks like builds succeeded but GH does not see it https://dev.azure.com/ms/vscode-python/_build/results?buildId=78806&view=logs&jobId=143eea66-4597-539b-c2e7-6e457837a569