Fix pointers count on iOS

[m-bert]

Description

In 2.15.0 we released partial support for macOS. In Tap and Rotation, instead of passing original touches parameter to keep iOS behavior, we changed that to NSSet with event object. This means that instead of having multiple UITouch objects in that set, we only had one object which cumulates all touches. Because we use [touches count] to find number of touches, change mentioned above resulted in obtaining wrong values.

Fixes #2754

Test plan

Tested on code from #2754

import React, { useState } from 'react';
import { Text, StyleSheet, View, ScrollView, Button } from 'react-native';
import { GestureDetector, Gesture } from 'react-native-gesture-handler';

export default function Home() {
  const [log, setLog] = useState<string[]>([]);

  const tap = Gesture.Tap()
    .minPointers(2)
    .runOnJS(true)
    .onBegin((event) => {
      console.log('onBegin', JSON.stringify({ event }));
      setLog((prev) => [`onBegin: ${JSON.stringify({ event })}`, ...prev]);
    })
    .onStart((event) => {
      console.log('onStart', JSON.stringify({ event }));
      setLog((prev) => [`onStart: ${JSON.stringify({ event })}`, ...prev]);
    })
    .onFinalize((event, success) => {
      console.log('onFinalize', { event, success });
      setLog((prev) => [
        `onEnd: ${JSON.stringify({ event })}; success:${success}`,
        ...prev,
      ]);
    });

  return (
    <View style={styles.container}>
      <Button title="Reset" onPress={() => setLog([])} />
      <GestureDetector gesture={tap}>
        <View style={styles.container}>
          {/* <ScrollView> */}
          {log.map((line, i) => (
            <Text key={i} style={[styles.log, i === 0 && styles.logNew]}>
              {line}
            </Text>
          ))}
          {/* </ScrollView> */}
        </View>
      </GestureDetector>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    width: '100%',
    height: '100%',
    backgroundColor: 'white',
  },
  log: {
    fontSize: 12,
    color: 'grey',
    padding: 5,
  },
  logNew: {
    backgroundColor: '#e6ffec',
    color: 'black',
  },
});

[levibuzolic]

Thanks @m-bert that's working as intended now, have tested with my minimal reproduction and in actual application code and it's behaving just like 2.14.1 again. 🙇‍♂️