Reactive expression hinting `$: x, fn()` raises TS error

[rixo]

Describe the bug
Reactive expression hinting raises TS error "Left side of comma operator is unused and has no side effects".

$: x, update()

AFAIK this is very idiomatic Svelte to mean "update when x changes", so this shouldn't be marked as error/warning.

To Reproduce
Paste the following in a .svelte file in VSCode:

<script lang="ts">
  let x: any

  const update = () => {}

  $: x, update()
</script>

x in the reactive expression is marked as error.

Expected behavior
There should be no TS errors for the above snippet.

System (please complete the following information):

• OS: Ubuntu
• IDE: VSCode
• Plugin/Package: Svelte for VSCode v105.7.0