Make Tintype snapshot mocks compatible with Jest 29

Summary: Use unparameterized `jest.fn()` mocks in the shared snapshot provider tests. The OSS package pins `types/jest` 29, which rejects the single function-type generic accepted by the xplat environment. Existing mock wrappers already provide the required return-value casts.

Reviewed By: aperez

Differential Revision: D116864954

fbshipit-source-id: eec94982c62ba558e6ca8f3a4e7e5403763bcc2c

Author: pdepetro

vscode/core/src/snapshot/__tests__/snapshot-provider.test.tsx

@@ -17,8 +17,8 @@ const mockShowErrorMessage = jest.fn();
 const mockShowInformationMessage = jest.fn();
 const mockShowWarningMessage = jest.fn();
 const mockShowSaveDialog = jest.fn();
-const mockStartDebugging = jest.fn<(...args: unknown[]) => Promise<boolean>>();
-const mockFsStat = jest.fn<(uri: unknown) => Promise<unknown>>();
+const mockStartDebugging = jest.fn();
+const mockFsStat = jest.fn();
 
 type StartDebuggingCall = [workspaceFolder: unknown, config: Record<string, unknown>];