feat(go-runner): collect Go toolchain environment information

[GuillaumeLagrange]

Integrate with the new instrument-hooks environment collection API to report Go toolchain metadata (version, OS, arch) alongside benchmark runs. Updates instrument-hooks to e86719c which adds the set_environment/write_environment C API.

Generated with AI Agent (Claude Code)

{
  "sections": {
    "Go": {
      "version": "go1.25.4",
      "arch": "amd64"
    }
  }
}

[codspeed-hq]

Merging this PR will not alter performance

✅ 48 untouched benchmarks
⏩ 1 skipped benchmark¹

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_{Comparing cod-2416-implement-toolchain-harvesting-for-node-python-and-go (7f7333f) with main (12ee23e)}

Footnotes

1. 1 benchmark was skipped, so the baseline result was used instead. If it was deleted from the codebase, click here and archive it to remove it from the performance reports. ↩

[adriencaccia]

Let's use go, to be able to use it as a slug