[General] Don't use context from useHandler

[j-piasecki]

Description

Instead of using context from useHandler to store data about the last received event, this PR introduces a global mutable object that holds a map in the UI runtime, allowing data to be stored by handler tags. This, along with the changes introduced in software-mansion/react-native-reanimated#9334, should significantly reduce the overhead of using gestures with Reanimated.

Test plan

Tested on Touchable stress test but added a Pan gesture. With this and the Reanimated change, the average dropped from 933ms to 810ms.

[Copilot]

Pull request overview

This PR replaces the per-handler useHandler context usage in the RNGH3 hook callback path with a shared mutable cache keyed by handlerTag, aiming to reduce Reanimated overhead for gesture updates.

Changes:

• Added a module-level mutable map in useReanimatedEventHandler to store lastUpdateEvent state by handler tag.
• Relaxed eventHandler update-path context handling so it no longer throws when context is absent.
• Extended the local Reanimated wrapper typings with makeMutable.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
packages/react-native-gesture-handler/src/v3/hooks/callbacks/useReanimatedEventHandler.ts	Replaces per-hook Reanimated context usage with a shared mutable handler-tag map in the UI runtime.
packages/react-native-gesture-handler/src/v3/hooks/callbacks/eventHandler.ts	Makes update/finalize logic tolerate missing context instead of throwing.
packages/react-native-gesture-handler/src/handlers/gestures/reanimatedWrapper.ts	Adds makeMutable to the local Reanimated type surface.

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