fix(Overflow): Update overflow menu when items are removed

[miroslavstastny]

Previous Behavior

In Overflow, when an OverflowItem was removed from the container, the overflow was updated only when the queue of visible items was changed by the removal.
As a result, when an overflowing item was removed, the overflow menu was not updated. Similarly, when all overflow items were removed, the overflow menu was not removed.

New Behavior

Whenever OverflowItem is removed while the Overflow is in observing state, force dispatch is triggered to update the overflow menu. This behavior matches the add logic.

Related Issue(s)

• Fixes [Feature]: Removing overflow items without unmounting an overflow item component #29509

[codesandbox-ci]

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[fabricteam]

Perf Analysis (@fluentui/react-components)

Scenario	Render type	Master Ticks	PR Ticks	Iterations	Status
FluentProviderWithTheme	virtual-rerender	38	34	10	Possible regression

All results

Scenario	Render type	Master Ticks	PR Ticks	Iterations	Status
Avatar	mount	617	656	5000
Button	mount	297	304	5000
Field	mount	1153	1132	5000
FluentProvider	mount	708	702	5000
FluentProviderWithTheme	mount	82	78	10
FluentProviderWithTheme	virtual-rerender	38	34	10	Possible regression
FluentProviderWithTheme	virtual-rerender-with-unmount	71	73	10
MakeStyles	mount	862	874	50000
Persona	mount	1782	1722	5000
SpinButton	mount	1405	1395	5000
SwatchPicker	mount	1518	1552	5000

[fabricteam]

📊 Bundle size report

Package & Exports	Baseline (minified/GZIP)	PR	Change
priority-overflow createOverflowManager	4.447 kB 1.853 kB	4.457 kB 1.856 kB	10 B 3 B
react-components react-components: entire library	1.139 MB 275.306 kB	1.139 MB 275.311 kB	10 B 5 B
react-overflow hooks only	12.86 kB 4.825 kB	12.87 kB 4.83 kB	10 B 5 B

Unchanged fixtures

Package & Exports	Size (minified/GZIP)
react-breadcrumb @fluentui/react-breadcrumb - package	117.263 kB 32.241 kB
react-components react-components: Button, FluentProvider & webLightTheme	71.55 kB 20.584 kB
react-components react-components: Accordion, Button, FluentProvider, Image, Menu, Popover	221.825 kB 62.568 kB
react-components react-components: FluentProvider & webLightTheme	44.037 kB 14.418 kB
react-portal-compat PortalCompatProvider	8.39 kB 2.64 kB

_{🤖 This report was generated against 1ccf6c23ddc4d125940ce23ea3788d0069665f67}

[fabricteam]

🕵 fluentuiv9 No visual regressions between this PR and main