[pickers] Prevent focus restoration from reopening picker

[JAYATIAHUJA]

Summary

When a desktop picker closes after selecting a date, PickerPopper restores focus to the field. With keepOpenDuringFieldFocus, that programmatic focus was treated as user focus and immediately reopened the picker.

This change:

• adds a private isRestoringFocusRef to the picker context
• marks the focus restoration window in PickerPopper
• prevents PickerFieldUI from reopening only during that programmatic restoration
• adds regression coverage proving selection stays closed while later keyboard focus still opens the picker

Closes #23089

Changelog

[pickers] Prevent keepOpenDuringFieldFocus from reopening the picker after a selection closes it.

Testing

• pnpm test:unit --project "x-date-pickers" --run <affected test files> --maxWorkers=1 — 39 tests passed
• ESLint on the five changed files
• pnpm --filter "@mui/x-date-pickers" run typescript
• pnpm --filter "@mui/x-date-pickers-pro" run typescript
• Prettier check on the five changed files

Local environment note: a complete serialized x-date-pickers run was also attempted and reported 11 failures in untouched MobileDateTimePicker/YearCalendar paths, primarily 5-second timeouts and Material UI transition act(...) warnings. The directly affected suites and static checks above are green.

• I have followed (at least) the PR section of the contributing guide.

[code-infra-dashboard]

Deploy preview

https://deploy-preview-23321--material-ui-x.netlify.app/

Bundle size

Bundle	Parsed size	Gzip size
@mui/x-data-grid	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-pro	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-premium	0B(0.00%)	0B(0.00%)
@mui/x-charts	0B(0.00%)	0B(0.00%)
@mui/x-charts-pro	0B(0.00%)	0B(0.00%)
@mui/x-charts-premium	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers	🔺+183B(+0.09%)	🔺+60B(+0.10%)
@mui/x-date-pickers-pro	🔺+180B(+0.07%)	🔺+59B(+0.08%)
@mui/x-tree-view	0B(0.00%)	0B(0.00%)
@mui/x-tree-view-pro	0B(0.00%)	0B(0.00%)
@mui/x-scheduler	0B(0.00%)	0B(0.00%)
@mui/x-scheduler-premium	0B(0.00%)	0B(0.00%)
@mui/x-chat	0B(0.00%)	0B(0.00%)
@mui/x-license	0B(0.00%)	0B(0.00%)

Details of bundle changes

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Check out the code infra dashboard for more information about this PR.

[JAYATIAHUJA]

Follow-up on the initial browser CI failures: both Chromium jobs failed at the same immediate dialog-removal assertion while the popper exit transition was still running. I pushed 9ba4f80 to use the repository's established transition-safe waitFor pattern.

Verified locally after the change:

• Chromium: 2/2 tests passed
• jsdom: 2/2 tests passed
• ESLint and Prettier passed
• @mui/x-date-pickers and @mui/x-date-pickers-pro TypeScript checks passed

The required PR type-label check needs type: bug; I do not have permission to apply labels in the upstream repository.