Deny unknown keys in settings in JSON schema so user gets warnings but settings still parses (#30583)

Closes #ISSUE

Release Notes:

- Improved checking of Zed settings so that unrecognized keys show
warnings while editing them

crates/call/src/call_settings.rs

@@ -12,6 +12,7 @@ pub struct CallSettings {
 
 /// Configuration of voice calls in Zed.
 #[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[schemars(deny_unknown_fields)]
 pub struct CallSettingsContent {
     /// Whether the microphone should be muted when joining a channel or a call.
     ///