Closes https://github.com/zed-industries/zed/issues/60763

Follow-up to #60000. Global language server exclusions were added to
per-language settings without removing an explicit enable for the same
server, allowing it to still start.

For example, this setting should disable `vtsls` for every language:

```json
{
  "language_servers": ["!vtsls", "..."]
}
```

However, TypeScript’s default configuration explicitly enables `vtsls`,
causing it to still start.

Release Notes:

- Fixed language servers starting despite being disabled globally.