BPF_MAP_TYPE_HASH operation cost higher on Windows vs Linux

The test "BPF_MAP_TYPE_HASH update" shows significantly higher cost on Windows vs Linux:

Windows:
```
BPF_MAP_TYPE_HASH read,120,119
BPF_MAP_TYPE_HASH update,1069,1075
BPF_MAP_TYPE_HASH update/read,907,140
BPF_MAP_TYPE_HASH replace,1737,1748
```

Linux:
```
BPF_MAP_TYPE_HASH read,38,38
BPF_MAP_TYPE_HASH update,171,169
BPF_MAP_TYPE_HASH update/read,119,80
BPF_MAP_TYPE_HASH replace,256,257
```

Use the named "BPF_MAP_TYPE_HASH update" test as the entry point and reproduce its timings on Windows and Linux. Compare the read, update, update/read, and replace results to identify the source of the Windows overhead. Done should include a verified explanation and improved Windows costs, with the benchmark results rerun.

Written by the indexing model from the issue text.