chore(ci): reduce build base venv job from 8 to 6

[brettlangdon]

We only build for 6 Python versions, so 2 runners spin up, do nothing, and stop.

Checklist

• [x] Change(s) are motivated and described in the PR description
• [x] Testing strategy is described if automated tests are not included in the PR
• [x] Risks are described (performance impact, potential for breakage, maintainability)
• [x] Change is maintainable (easy to change, telemetry, documentation)
• [x] Library release note guidelines are followed or label changelog/no-changelog is set
• [x] Documentation is included (in-code, generated user docs, public corp docs)
• [x] Backport labels are set (if applicable)
• [x] If this PR changes the public interface, I've notified @DataDog/apm-tees.

Reviewer Checklist

• [x] Title is accurate
• [x] All changes are related to the pull request's stated goal
• [x] Description motivates each change
• [x] Avoids breaking API changes
• [x] Testing strategy adequately addresses listed risks
• [x] Change is maintainable (easy to change, telemetry, documentation)
• [x] Release note makes sense to a user of the library
• [x] Author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• [x] Backport labels are set in a manner that is consistent with the release branch maintenance policy

[datadog-dd-trace-py-rkomorn[bot]]

Datadog Report

Branch report: brettlangdon/build.num.jobs Commit report: a18fe6f Test service: dd-trace-py

:white_check_mark: 0 Failed, 136283 Passed, 40083 Skipped, 8h 44m 3.1s Total duration (2h 19m 39.05s time saved)

[pr-commenter[bot]]

Benchmarks

Benchmark execution time: 2024-06-26 18:52:27

Comparing candidate commit 249a7d6404a74426a821734c71f5c915d2c3e190 in PR branch brettlangdon/build.num.jobs with baseline commit 6a9712d1bf20bfbcfc83aecf21f04b6289526b5c in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 221 metrics, 9 unstable metrics.