[PGO] Remove calls to `__llvm_orderfile_dump()` in `instrprof-api.c` test (#79150)

https://github.com/llvm/llvm-project/pull/78285 added a test which calls
`__llvm_orderfile_dump()`, a functionality that is not supported on many
platforms. This PR removes the call to `__llvm_orderfile_dump()` to
avoid it failing on unsupported platforms, and turn on the test for
Windows, so we test the rest of the API that are supported.