Move env.shell to stable

src/vs/vscode.d.ts

@@ -6079,6 +6079,12 @@ declare module 'vscode' {
 		 */
 		export const remoteName: string | undefined;
 
+		/**
+		 * The detected default shell for the extension host, this is overridden by the
+		 * `terminal.integrated.shell` setting for the extension host's platform.
+		 */
+		export const shell: string;
+
 		/**
 		 * Opens an *external* item, e.g. a http(s) or mailto-link, using the
 		 * default application.

src/vs/vscode.proposed.d.ts

@@ -623,12 +623,6 @@ declare module 'vscode' {
 		 */
 		export const logLevel: LogLevel;
 
-		/**
-		 * The detected default shell for the extension host, this is overridden by the
-		 * `terminal.integrated.shell` setting for the extension host's platform.
-		 */
-		export const shell: string;
-
 		/**
 		 * An [event](#Event) that fires when the log level has changed.
 		 */

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

@@ -258,7 +258,6 @@ export function createApiFactory(
 				return extHostClipboard;
 			},
 			get shell() {
-				checkProposedApiEnabled(extension);
 				return extHostTerminalService.getDefaultShell(configProvider);
 			},
 			openExternal(uri: URI) {