fix(Suspense): avoid unmount activeBranch twice if wrapped in transition

[edison1105]

close #7966
the root cause is that the suspense resolves before the fallback node is mounted. This caused component B to be unmounted twice, causing this issue when it was unmounted the second time. see simplified demo
Notice the Console, unmount was printed twice.

[github-actions]

Size Report

Bundles

File	Size	Gzip	Brotli
runtime-dom.global.prod.js	90.2 kB (+83 B)	34.6 kB (+19 B)	31.1 kB (-4 B)
vue.global.prod.js	147 kB (+83 B)	54 kB (+20 B)	48.1 kB (+24 B)

Usages

Name	Size	Gzip	Brotli
createApp	49.6 kB	19.5 kB	17.8 kB
createSSRApp	53.2 kB	20.9 kB	19.1 kB
defineCustomElement	51.9 kB	20.2 kB	18.5 kB
overall	63.2 kB (+83 B)	24.5 kB (+25 B)	22.3 kB (+55 B)

[pikax]

@edison1105 I don't think the solution is good enough, from what I could gather this is caused by the renderer.ts

Basically the unmount is being called multiple times on the vnode, I wonder if we could replace the condition on suspense with a non altering flag on suspense.

I suppose it would make sense the vnode to know it has been unmounted therefore if unmounted is called again it should be ignored, some input from @yyx990803 would be great :)

[edison1105]

@pikax
That's a great idea. I changed the solution.

[edison1105]

/ecosystem-ci run

[vue-bot]

📝 Ran ecosystem CI: Open

suite	result	latest scheduled
language-tools	✅ success	✅ success
nuxt	✅ success	✅ success
pinia	✅ success	❌ failure
quasar	✅ success	✅ success
radix-vue	✅ success	✅ success
router	✅ success	✅ success
test-utils	✅ success	✅ success
vant	✅ success	✅ success
vite-plugin-vue	✅ success	✅ success
vitepress	✅ success	✅ success
vue-i18n	✅ success	✅ success
vue-macros	✅ success	✅ success
vuetify	❌ failure	✅ success
vueuse	✅ success	✅ success
vue-simple-compiler	✅ success	✅ success