Bump the ESLint dev dependencies

[jtpio]

References

#9297

Attempt to address the first item in #9297 (comment)

However it looks like the latest tsutils hasn't been update yet:

• https://github.com/ajafff/tsutils/blob/8fceea350ce528bd911ea6eca4cce62ba83ee548/package.json#L53
• Update Dependencies Comp. ajafff/tsutils#123

$ jlpm why tsutils
yarn why v1.21.1
[1/4] Why do we have the module "tsutils"...?
[2/4] Initialising dependency graph...
[3/4] Finding dependency...
[4/4] Calculating file sizes...
=> Found "tsutils@3.17.1"
info Reasons this module exists
   - "_project_#@typescript-eslint#eslint-plugin" depends on it
   - Hoisted from "_project_#@typescript-eslint#eslint-plugin#tsutils"
   - Hoisted from "_project_#@typescript-eslint#parser#@typescript-eslint#typescript-estree#tsutils"
info Disk size without dependencies: "408KB"
info Disk size with unique dependencies: "464KB"
info Disk size with transitive dependencies: "464KB"
info Number of shared dependencies: 1
Done in 1.46s.

Code changes

Dev dependencies update.

User-facing changes

None

Backwards-incompatible changes

None

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[jtpio]

jest/no-conditional-expect and jest/valid-title are now part of the recommended ruleset:

https://github.com/jest-community/eslint-plugin-jest/blob/master/CHANGELOG.md#2400-2020-09-04

https://github.com/jupyterlab/jupyterlab/pull/9391/checks?check_run_id=1435555937

[jtpio]

f6ec55d marks these 2 rules as warnings. So they could be tackled separately for example in #9392

[blink1073]

Thanks!