feat: add experimental --exclude-allocations setting

[not-matthias]

No description provided.

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

✅ 7 untouched benchmarks

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_{Comparing cod-3016-add-runneraction-setting-to-exclude-memory-allocators (ca7c0f6) with main (7ce2c98)}

[greptile-apps]

Greptile Summary

This PR adds an experimental setting to exclude allocation time from measurement results. The main changes are:

• A new --unstable-exclude-allocations CLI flag and environment variable.
• Propagation of the setting through executor and run metadata config.
• Upload metadata serialization that includes the setting only when enabled.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.
• The default upload payload remains unchanged when the new setting is disabled.

Important Files Changed

Filename	Overview
src/cli/experimental.rs	Adds the experimental CLI flag and forwards it through the existing experimental flags list.
src/executor/config.rs	Adds the setting to orchestrator and executor configuration with a default disabled value.
src/run_environment/provider.rs	Includes the setting when building runner metadata for uploads.
src/upload/interfaces.rs	Adds the upload metadata field and skips it when disabled.
src/upload/upload_metadata.rs	Updates metadata hash tests for the new runner field.

_{Reviews (3): Last reviewed commit: "feat: add experimental --exclude-allocat..." | Re-trigger Greptile}