test(benchmark.js): use real root-frame helpers in core mock

The integ test deep-mocks @codspeed/core, so wrapWithRootFrame and
wrapWithRootFrameSync returned non-callable mocks once the plugin began
wrapping benchmarks through them. Bind both to the actual implementations,
matching getGitDir/getCallingFile.

Author: not-matthias

packages/benchmark.js-plugin/tests/index.integ.test.ts

@@ -11,6 +11,8 @@ jest.mock("@codspeed/core", () => {
   const actual = jest.requireActual("@codspeed/core");
   mockCore.getGitDir = actual.getGitDir;
   mockCore.getCallingFile = actual.getCallingFile;
+  mockCore.wrapWithRootFrame = actual.wrapWithRootFrame;
+  mockCore.wrapWithRootFrameSync = actual.wrapWithRootFrameSync;
   return mockCore;
 });