BUG Svelte 5: #key does not prevent $props() from changing if key is $derived

[python273]

Describe the bug

<script>
import Session from './Session.svelte'
let x = $state("qwe");
let sessionId = $derived(x + '$');
</script>

<button onclick={() => { x = ''+new Date().valueOf(); }}>Update</button>
{#key sessionId}
	<Session {sessionId}/>
{/key}

Session gets updated value before destruction.

Reproduction

If you click "Update" and look into console, Sessions logs updated sessionId in onDestroy:

https://svelte.dev/playground/hello-world?version=5.25.7#H4sIAAAAAAAAE3WRzU7DMBCEX8UyleKoVXJP00hIPcABcUCcCIcQb8Gqaxt7m7SK8u7YTegPtMcdz87ufu6oqjZAM_oAUmrSais5YcAFAo_pjK6EBEezt47i3gRfELw-dt0bk7gGJAbto3JwTa-1QlDoY2juaisMFqUSG6MtkhdwTmhFVlZvSJSkYz02R6WSgGRHFmTisEJgJf1uoaTxfHhxg_2RBwcHKxrgbEemJJpEwZOnx4G--Ngi-lla1VLU60XHYrIoSHfIj6KpgpYsw5A4aSq5hecVi-ek74tXw72cp0O_z-ru1rA_De99Oua_p3QnPQ3e1Hu9w4NA2CHN0G6hn90Aenn_JdR_b1fBljii7fyhS3Bo9Z70I-Aj1hIDvlp7q_IRB4BPFX4ltlJcb1iAV6If4PD8oIDZWG3caJgI5QzUyM6SZicwg-m4BhuBB3EI1xISqT9ZxAdHNCM3kkJPH__9US6a4my9PA3CJel3X1VCtkJxmq0q6aD_AcXJk9T1AgAA

Without $derived, onDestroy logs the correct value (though $inspect logs updated value):

https://svelte.dev/playground/hello-world?version=5.25.7#H4sIAAAAAAAAE3WRQU-DMBiG_0pTlwCRwJ0xEpMd9GA8GE_igdEPbVba2n4bLoT_biu4Dd2OfXm_p_0eeiqrFmhG70EIRTplBCMhMI7AIhrThguwNHvtKR607_nA5dPUndaJ3YNAn20qC5fyWkkEiQ5Dc1sbrrEoJW-1MkiewVquJGmMakmQpNN5Gg5KKQCJHcMHRlZkYbFCCEv62UFJo2Up8_QIdYfNDtHxlKwFr7erPozIqiD9jBEEtxI6svagKNlXYgdPTRgtyTAUL5q5OE9HjmP2N1s4nMYHdwvmv8_uT3nqu6nruoZbGuELaYZmB0N8Rd5817nAf98uSixx0ti7hddg0agDGSaZR4Uleom1clXpED8KHiv8SEwlmWpDL7FEd4HF84W8bG2UtlNhwaXVUGN4RopPYsbS8RnhJN6HI1wJSIR6DwM2NoKYXCH5mSH6-2cZ3xdnz8tTH8xNv7lTxUXHJaNZUwkLwzc9rcZv4QIAAA==

Logs

System Info

-

Severity

annoyance