GH-33726: [CI][Go] Set host name in Go benchmarks

[alistaire47]

Closes #33726; see issue for comprehensive explanation. cc @zeroshade

Rationale for this change

Go benchmarks are sending host names from runners that vary slightly, preventing us from seeing the full history of the benchmarks on Conbench.

What changes are included in this PR?

Sets host name in Go benchmarks via environment variable so benchmark history will be available on Conbench.

Are these changes tested?

Yes, for the benchadapt code that will pick it up: https://github.com/conbench/conbench/blob/main/benchadapt/python/tests/test_result.py#L107-L114

Are there any user-facing changes?

No

• Closes: Set consistent host name in Go benchmarks in CI #33726

[github-actions]

• Closes: Set consistent host name in Go benchmarks in CI #33726

[github-actions]

⚠️ GitHub issue #33726 has been automatically assigned in GitHub to PR creator.

[zeroshade]

LGTM

[assignUser]

+1

[ursabot]

Benchmark runs are scheduled for baseline = 7319250 and contender = 705e04b. 705e04b is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Finished ⬇️0.0% ⬆️0.0%] ec2-t3-xlarge-us-east-2
[Failed ⬇️0.69% ⬆️0.0%] test-mac-arm
[Finished ⬇️0.26% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️1.03% ⬆️0.16%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 705e04bb ec2-t3-xlarge-us-east-2
[Finished] 705e04bb test-mac-arm
[Finished] 705e04bb ursa-i9-9960x
[Finished] 705e04bb ursa-thinkcentre-m75q
[Finished] 73192505 ec2-t3-xlarge-us-east-2
[Failed] 73192505 test-mac-arm
[Finished] 73192505 ursa-i9-9960x
[Finished] 73192505 ursa-thinkcentre-m75q
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java