Use v0.0.6 of the `zed_extension_api` for extensions that need it (#10324)

This PR updates the extensions dependent on v0.0.6 of the
`zed_extension_api` crate to use the now-published version on crates.io
instead of a path dependency.

The impacted extensions are:

- `dart`
- `gleam`
- `haskell`
- `svelte`


Release Notes:

- N/A