Use half of the available cores when in watchAll mode

[brapifra]

Summary

Fixes #9116

Test plan

Added a new condition in the Returns based on the number of cpus test of the packages/jest-config/src/__tests__/getMaxWorkers.test.ts file

[facebook-github-bot]

Hi brapifra! Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file.In order for us to review and merge your code, please sign at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need to sign the corporate CLA.

If you have received this in error or have any questions, please contact us at [email protected]. Thanks!

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[SimenB]

Thanks! Could you update the changelog as well?

[brapifra]

Done @SimenB 😄

[codecov-io]

Codecov Report

Merging #9117 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #9117      +/-   ##
==========================================
+ Coverage   64.73%   64.73%   +<.01%     
==========================================
  Files         277      277              
  Lines       11707    11709       +2     
  Branches     2875     2875              
==========================================
+ Hits         7578     7580       +2     
  Misses       3512     3512              
  Partials      617      617

Impacted Files	Coverage Δ
packages/jest-config/src/getMaxWorkers.ts	100% <100%> (ø)	⬆️

---

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 ed07de2...7daffce. Read the comment docs.

[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.