feat(effectScope): add onDispose method

[Alfred-Skyblue]

When the effectScope is not active, we can only listen to its dispose in the following way:

const scope = effectScope();

scope.run(() => {});

scope.cleanups.push(() => {
  /* code */
});

Although this method solves the current problem, it is rather cumbersome. In this PR, I have added an onDispose method, allowing us to listen to the dispose of effectScope in the following manner:

const scope = effectScope();

scope.run(() => {});

scope.onDispose(() => {
  /* code */
});

[github-actions]

Size Report

Bundles

File	Size	Gzip	Brotli
runtime-dom.global.prod.js	94 kB (+3.27 kB)	35.5 kB (+979 B)	31.9 kB (+859 B)
vue.global.prod.js	151 kB (+3.27 kB)	54.8 kB (+1.01 kB)	49 kB (+878 B)

Usages

Name	Size	Gzip	Brotli
createApp	53.9 kB (+3.19 kB)	20.9 kB (+1.02 kB)	18.9 kB (+843 B)
createSSRApp	57.3 kB (+3.19 kB)	22.2 kB (+997 B)	20.1 kB (+833 B)
defineCustomElement	56.2 kB (+3.19 kB)	21.6 kB (+1.01 kB)	19.6 kB (+807 B)
overall	67.7 kB (+3.25 kB)	25.9 kB (+974 B)	23.4 kB (+812 B)