Fixes #57946: Deprecate identifier in tasks.json.

src/vs/workbench/parts/tasks/electron-browser/jsonSchema_v2.ts

@@ -271,7 +271,8 @@ const version: IJSONSchema = {
 
 const identifier: IJSONSchema = {
 	type: 'string',
-	description: nls.localize('JsonSchema.tasks.identifier', 'A user defined identifier to reference the task in launch.json or a dependsOn clause.')
+	description: nls.localize('JsonSchema.tasks.identifier', 'A user defined identifier to reference the task in launch.json or a dependsOn clause.'),
+	deprecationMessage: nls.localize('JsonSchema.tasks.identifier.deprecated', 'User defined identifiers are deprecated. Use task identifier literals instead when referencing a task in a dependsOn property or in a launch.json file.')
 };
 
 const options: IJSONSchema = Objects.deepClone(commonSchema.definitions.options);