chore: replace deprecated `jest.autoRun` in `.vscode/settings.json` (#66609)
### Why?

Since `jest.autoRun` in `.vscode/settings.json` is deprecated, this PR
replaces it with an equivalent setting using the recommended migration
guide.
> Starting from v6.1.0, if no runMode is defined in settings.json, the
extension will automatically generate one using legacy settings
(autoRun, showCoverageOnLoad). To migrate, simply use the "Jest: Save
Current RunMode" command from the command palette to update the setting,
then remove the deprecated settings.
x-ref:
https://github.com/jest-community/vscode-jest/blob/master/README.md#autorun