[facebook/react] Bug: ReactProfilerTimer transition timers are global, causing conflicts with concurrent transitions

### ROOT CAUSE The global variables in `ReactProfilerTimer.js` are shared across all transition lanes, leading to data conflicts when multiple transitions occur concurrently. This causes inaccurate profiling data and potential race conditions. ### CODE FIX To fix this issue, we refactor the `ReactProfilerTimer.js` module to use a `Map` where each lane ID maps to its specific timing data. Here's how the code can be updated: ```javascript import {Lane} from 'react-reconciler/src/ReactTypes'; const transitionTimers = new Map(); export function recordTransitionStart(lane: Lane) { if (!transitionTimers.has(lane)) { transitionTimers.set(lane, { startTime: -1, updateTime: -1, updateType: null, clampTime: -0, }); } const timers = transitionTimers.get(lane); timers.startTime = Date.now(); } export function recordTransitionUpdate(lane: Lane, type: string) { const timers = transitionTimers.get(lane); timers.updateTime = Date.now(); timers.updateType = type; } export function recordTransitionClamp(lane: Lane, clampTime: number) { const timers = transitionTimers.get(lane); timers.clampTime = clampTime; } export function getTransitionTimer(lane: Lane): any { return transitionTimers.get(lane); } ``` This solution ensures each lane's timing data is isolated, preventing conflicts and ensuring accurate profiling.