src/vs/platform/configuration/common/configurationRegistry.ts/ConfigurationRegistry/deregisterDefaultConfigurations
class ConfigurationRegistry:	public deregisterDefaultConfigurations(defaultConfigurations: IConfigurationDefaults[]): void {
		const properties: string[] = [];
		for (const { overrides, source } of defaultConfigurations) {
			for (const key in overrides) {
				const configurationDefaultsOverride = this.configurationDefaultsOverrides.get(key);
				const id = types.isString(source) ? source : source?.id;
				const configurationDefaultsOverrideSourceId = types.isString(configurationDefaultsOverride?.source) ? configurationDefaultsOverride?.source : configurationDefaultsOverride?.source?.id;
				if (id !== configurationDefaultsOverrideSourceId) {
					continue;
				}
				properties.push(key);
				this.configurationDefaultsOverrides.delete(key);
				if (OVERRIDE_PROPERTY_REGEX.test(key)) {
					delete this.configurationProperties[key];
					delete this.defaultLanguageConfigurationOverridesNode.properties![key];
				} else {
					const property = this.configurationProperties[key];
					if (property) {
						this.updatePropertyDefaultValue(key, property);
						this.updateSchema(key, property);
					}
				}
			}
		}

		this.updateOverridePropertyPatternKey();
		this._onDidSchemaChange.fire();
		this._onDidUpdateConfiguration.fire({ properties, defaultsOverrides: true });
	}