Finalize TerminalOptions.runInBackground API

Fixes #75278

src/vs/vscode.d.ts

@@ -6988,6 +6988,15 @@ declare module 'vscode' {
 		 * must be provided as nothing will be inherited from the process or any configuration.
 		 */
 		strictEnv?: boolean;
+
+		/**
+		 * When enabled the terminal will run the process as normal but not be surfaced to the user
+		 * until `Terminal.show` is called. The typical usage for this is when you need to run
+		 * something that may need interactivity but only want to tell the user about it when
+		 * interaction is needed. Note that the terminals will still be exposed to all extensions
+		 * as normal.
+		 */
+		runInBackground?: boolean;
 	}
 
 	/**

src/vs/vscode.proposed.d.ts

@@ -1084,17 +1084,6 @@ declare module 'vscode' {
 
 	//#region Terminal
 
-	export interface TerminalOptions {
-		/**
-		 * When enabled the terminal will run the process as normal but not be surfaced to the user
-		 * until `Terminal.show` is called. The typical usage for this is when you need to run
-		 * something that may need interactivity but only want to tell the user about it when
-		 * interaction is needed. Note that the terminals will still be exposed to all extensions
-		 * as normal.
-		 */
-		runInBackground?: boolean;
-	}
-
 	/**
 	 * An [event](#Event) which fires when a [Terminal](#Terminal)'s dimensions change.
 	 */

src/vs/workbench/api/node/extHost.api.impl.ts

@@ -493,7 +493,6 @@ export function createApiFactory(
 			},
 			createTerminal(nameOrOptions?: vscode.TerminalOptions | string, shellPath?: string, shellArgs?: string[] | string): vscode.Terminal {
 				if (typeof nameOrOptions === 'object') {
-					nameOrOptions.runInBackground = nameOrOptions.runInBackground && extension.enableProposedApi;
 					return extHostTerminalService.createTerminalFromOptions(nameOrOptions);
 				}
 				return extHostTerminalService.createTerminal(<string>nameOrOptions, shellPath, shellArgs);