Describe the bug
I try to use transitions in each of my data ({#each}) that I get after my Promise resolves. But when I re-assign it to the variable that holds the Promise, the displayed data actually increases.

Discord link => https://discord.com/channels/457912077277855764/653341885674553345/791014063496101898

Logs
Nothing shows in the console

To Reproduce
https://svelte.dev/repl/99c98342054542ca9c9a82f97c0f200c?version=3.31.0
https://github.com/donnisnoni/svelte-127253y6123-bug/blob/bug/src/views/admin/rayon/Index.svelte#L54-L75
https://github.com/donnisnoni/svelte-127253y6123-bug/blob/bug/src/store/rayon.js#L22-L34

Expected behavior
The data is not duplicated/increased

Information about my Svelte project:

 System: OS: Linux 5.10 Linux Mint 20 (Ulyana) CPU: (4) x64 Intel(R) Core(TM) i3-4005U CPU @ 1.70GHz Memory: 445.32 MB / 3.76 GB Container: Yes Shell: 3.1.2 - /usr/bin/fish Binaries: Node: 14.15.1 - ~/nvm/node/v14.15.1/bin/node Yarn: 1.22.10 - ~/nvm/node/v14.15.1/bin/yarn npm: 6.14.9 - ~/nvm/node/v14.15.1/bin/npm Browsers: Chrome: 87.0.4280.88 npmPackages: svelte: ^3.31.0 => 3.31.0  vite: ^1.0.0-rc.13 => 1.0.0-rc.13 

Additional context
Add any other context about the problem here.