fix: Make withDecay compatible with withRepeat

[patrycjakalinska]

Summary

As it was discovered in #6757, withRepeat run along with withDecay triggered repeat only once, even if the number of repeats was greater. withDecay relies on the value of velocity. The initialVelocity is the velocity provided (or default), and during the animation, the velocity value decreases, causing the animated object to slowly stop. The problem was, after first repeat the velocity was already decreased to almost zero and the animation could not run, as it had no momentum.
I was able to fix that by adjusting finished prop, and reseting velocity to initial value, if finished is true.

Fixes #6757

Before:

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2024-11-25.at.12.07.07.mp4

After:

Screen.Recording.2024-11-28.at.14.18.54.mov

Test plan

Run provided code snipped on Fabric example

Code snipped provided in issue

import React from 'react';
import { View, Pressable, Text, StyleSheet } from 'react-native';
import Animated, {
  useAnimatedStyle,
  useSharedValue,
  withDecay,
  withRepeat,
} from 'react-native-reanimated';
import {
  GestureHandlerRootView,
  GestureDetector,
  Gesture,
} from 'react-native-gesture-handler';

const ballSize = 100;

export default function EmptyExample() {
  const position = useSharedValue(1);

  const animatedStyle = useAnimatedStyle(() => ({
    transform: [{ translateY: position.value }],
  }));

  const tap = Gesture.Tap().onStart(() => {
    position.value = withRepeat(
      withDecay({ velocity: 200, clamp: [-50, 100] }),
      5
    );
    // position.value = withDecay({ velocity: 200, clamp: [-500, 500] });
  });

  return (
    <GestureHandlerRootView style={{ flex: 1 }}>
      <View
        style={{ flex: 1, justifyContent: 'center', backgroundColor: 'red' }}>
        <GestureDetector gesture={tap}>
          <View
            style={{
              flex: 1,
              alignItems: 'center',
              justifyContent: 'center',
              flexDirection: 'column',
            }}>
            <Animated.View style={[styles.ball, animatedStyle]} />
          </View>
        </GestureDetector>
      </View>
    </GestureHandlerRootView>
  );
}
const styles = StyleSheet.create({
  ball: {
    width: ballSize,
    height: ballSize,
    borderRadius: ballSize / 2,
    backgroundColor: 'black',
    margin: 30,
  },
});