Select component can't be changed to no option selected if the component is not required.

[JayXTQ]

Describe the bug

When my users go to set a non-required field by accident, they can no longer set the select value to nothing, making it so they have to do the form all over again.

Reproduction

Make a select field with a random option, make sure it's not required, and set the value, and try to unset the value.

Flowbite version and System Info

System:
    OS: macOS 15.0.1
    CPU: (11) arm64 Apple M3 Pro
    Memory: 383.50 MB / 18.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.13.1 - /usr/local/bin/node
    npm: 10.5.2 - /usr/local/bin/npm
  Browsers:
    Safari: 18.0.1
  npmPackages:
    @sveltejs/kit: ^2.8.5 => 2.8.5 
    flowbite-svelte: ^0.47.3 => 0.47.3 
    svelte: ^4.2.19 => 4.2.19 
    vite: ^5.0.3 => 5.4.11