Overwriting a query that is not being used causes the request to happen

[Thiagolino8]

Describe the bug

When overwriting a query that is being used, the request is canceled, but otherwise the request occurs
If the query being overwritten does not yet exist, as in the case of an optimistic update when creating a new item, this results in an error

Reproduction

Reproduction steps: Just create a new post
https://stackblitz.com/edit/sveltejs-kit-template-default-xzmxugj1

Logs

something went horribly wrong: invalid_snippet Could not `{@render}` snippet due to the expression being `null` or `undefined`. Consider using optional chaining `{@render snippet?.()}` https://svelte.dev/e/invalid_snippet

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 20.19.1 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.8.2 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    @sveltejs/adapter-auto: ^6.0.1 => 6.0.1 
    @sveltejs/kit: ^2.27.0 => 2.27.0 
    @sveltejs/vite-plugin-svelte: ^6.1.0 => 6.1.0 
    svelte: ^5.37.2 => 5.37.2 
    vite: ^7.0.6 => 7.0.6

Severity

blocking an upgrade

Additional Information

No response