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/settings/src/settings_store.rs

@@ -1966,7 +1966,8 @@ mod tests {
     }
 
     #[derive(Default, Clone, Serialize, Deserialize, JsonSchema)]
-    struct UserSettingsJson {
+    #[schemars(deny_unknown_fields)]
+    struct UserSettingsContent {
         name: Option<String>,
         age: Option<u32>,
         staff: Option<bool>,
@@ -1974,7 +1975,7 @@ mod tests {
 
     impl Settings for UserSettings {
         const KEY: Option<&'static str> = Some("user");
-        type FileContent = UserSettingsJson;
+        type FileContent = UserSettingsContent;
 
         fn load(sources: SettingsSources<Self::FileContent>, _: &mut App) -> Result<Self> {
             sources.json_merge()
@@ -2008,6 +2009,7 @@ mod tests {
     }
 
     #[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
+    #[schemars(deny_unknown_fields)]
     struct MultiKeySettingsJson {
         key1: Option<String>,
         key2: Option<String>,
@@ -2046,6 +2048,7 @@ mod tests {
     }
 
     #[derive(Clone, Default, Debug, Serialize, Deserialize, JsonSchema)]
+    #[schemars(deny_unknown_fields)]
     struct JournalSettingsJson {
         pub path: Option<String>,
         pub hour_format: Option<HourFormat>,
@@ -2076,6 +2079,7 @@ mod tests {
     }
 
     #[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
+    #[schemars(deny_unknown_fields)]
     struct LanguageSettingEntry {
         language_setting_1: Option<bool>,
         language_setting_2: Option<bool>,