Fix a few more type assertions (#223138)

For #211878

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

@@ -7,7 +7,7 @@ import { AsyncIterableObject } from 'vs/base/common/async';
 import { CancellationTokenSource } from 'vs/base/common/cancellation';
 import * as errors from 'vs/base/common/errors';
 import { Emitter, Event } from 'vs/base/common/event';
-import { combinedDisposable, IDisposable } from 'vs/base/common/lifecycle';
+import { combinedDisposable } from 'vs/base/common/lifecycle';
 import { Schemas, matchesScheme } from 'vs/base/common/network';
 import Severity from 'vs/base/common/severity';
 import { URI } from 'vs/base/common/uri';
@@ -1206,17 +1206,17 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 			},
 			registerFileSearchProviderNew: (scheme: string, provider: vscode.FileSearchProviderNew) => {
 				checkProposedApiEnabled(extension, 'fileSearchProviderNew');
-				return <IDisposable>{ dispose: () => { } };
+				return { dispose: () => { } };
 			},
 			registerTextSearchProviderNew: (scheme: string, provider: vscode.TextSearchProviderNew) => {
 				checkProposedApiEnabled(extension, 'textSearchProviderNew');
-				return <IDisposable>{ dispose: () => { } };
+				return { dispose: () => { } };
 			},
 			registerAITextSearchProviderNew: (scheme: string, provider: vscode.AITextSearchProviderNew) => {
 				// there are some dependencies on textSearchProvider, so we need to check for both
 				checkProposedApiEnabled(extension, 'aiTextSearchProviderNew');
 				checkProposedApiEnabled(extension, 'textSearchProviderNew');
-				return <IDisposable>{ dispose: () => { } };
+				return { dispose: () => { } };
 			},
 			registerRemoteAuthorityResolver: (authorityPrefix: string, resolver: vscode.RemoteAuthorityResolver) => {
 				checkProposedApiEnabled(extension, 'resolvers');