remove getExtension workaround (#159758)

fixes #153320

Author: jrieken

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

@@ -92,7 +92,6 @@ import { ExtHostInteractive } from 'vs/workbench/api/common/extHostInteractive';
 import { combinedDisposable } from 'vs/base/common/lifecycle';
 import { checkProposedApiEnabled, ExtensionIdentifierSet, isProposedApiEnabled } from 'vs/workbench/services/extensions/common/extensions';
 import { DebugConfigurationProviderTriggerKind } from 'vs/workbench/contrib/debug/common/debug';
-import { equalsIgnoreCase } from 'vs/base/common/strings';
 import { IExtHostTelemetryLogService } from 'vs/workbench/api/common/extHostTelemetryLogService';
 
 export interface IExtensionRegistries {
@@ -395,11 +394,6 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 
 		const extensions: typeof vscode.extensions = {
 			getExtension(extensionId: string, includeFromDifferentExtensionHosts?: boolean): vscode.Extension<any> | undefined {
-				if (equalsIgnoreCase(extensionId, 'ms-vscode.references-view')) {
-					extHostApiDeprecation.report(`The extension 'ms-vscode.references-view' has been renamed.`, extension, `Use 'vscode.references-view' instead.`);
-					extensionId = 'vscode.references-view';
-				}
-
 				if (!isProposedApiEnabled(extension, 'extensionsAny')) {
 					includeFromDifferentExtensionHosts = false;
 				}