Add the commit hash to OpenTelemetry traces

Problem/Motivation

Once ✨ Add OpenTelemetry Application Performance Monitoring to core performance tests Fixed is committed to Drupal core, AND performance tests are running on gitlab pipelines AND we have a Grafana stack to report to, there are some improvements we can make to the output.

We want to show changes in core performance over time, to be able to track down which commit caused an improvement or regression, ideally we'd add the commit hash to the trace, then we know the exact version of core the test ran against.

This can then be used in two places:

1. In the Grafana tempo UI it will show as one of the trace attributes.

2. Potentially we could show the commit hash on the actual graph, although I haven't found a non-hacky way to do that yet. A hacky way is in this blog post: https://jorgelbg.me/2019/02/display-the-applications-version-in-your-gra...

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet