Revert cleaning cache changes on Windows

[anmyachev]

With unloaded DLL libraries, these changes are no longer necessary. However, two tests that hold a reference to the compiled kernel need to be adjusted - manually clear the cache (inside JITFunction object).

CI:

• https://github.com/intel/intel-xpu-backend-for-triton/actions/runs/12951798922 (passed)
• https://github.com/intel/intel-xpu-backend-for-triton/actions/runs/12955820922 (check status)

Blocked on #3251

Extra refs:

• tempfile seems to treat a file as a directory when processing an exception in the onerror() python/cpython#87319

[gshimansky]

This change was necessary if multiple processes compile the same kernel and try to put files (not only .pyd) into the same cache directory. It happens when you run tests with xdist and all workers use the same triton cache directory. A user program might behave in the same way too.

[anmyachev]

You are right, thank you!