ci: update system-tests GitHub Actions ref [backport 3.10]

[brettlangdon]

Backport from #13989 to 3.10 branch.

(cherry picked from commit b4bdef9)

Checklist

• PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[github-actions]

CODEOWNERS have been resolved as:

.github/workflows/system-tests.yml                                      @DataDog/python-guild @DataDog/apm-core-python

[github-actions]

Bootstrap import analysis

Comparison of import times between this PR and base.

Summary

The average import time from this PR is: 286 ± 5 ms.

The average import time from base is: 289 ± 5 ms.

The import time difference between this PR and base is: -2.6 ± 0.2 ms.

Import time breakdown

The following import paths have shrunk:

ddtrace.auto 2.025 ms (0.71%)

ddtrace.bootstrap.sitecustomize 1.335 ms (0.47%)

ddtrace.bootstrap.preload 1.335 ms (0.47%)

ddtrace.internal.remoteconfig.client 0.669 ms (0.23%)

ddtrace 0.689 ms (0.24%)

ddtrace.internal._unpatched 0.033 ms (0.01%)

json 0.033 ms (0.01%)

json.decoder 0.033 ms (0.01%)

re 0.033 ms (0.01%)

enum 0.033 ms (0.01%)

types 0.033 ms (0.01%)

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-07-15 12:22:30

Comparing candidate commit f7e8c78 in PR branch backport-13989-to-3.10 with baseline commit 1f8c272 in branch 3.10.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 548 metrics, 2 unstable metrics.