temp: run ci on 3.15

[KowalskiThomas]

Backport e13717f from #14735 to 3.15.

Co-authored-by: Emmett Butler [email protected]## Description

Testing

Risks

Additional Notes

[github-actions]

Bootstrap import analysis

Comparison of import times between this PR and base.

Summary

The average import time from this PR is: 268 ± 3 ms.

The average import time from base is: 270 ± 3 ms.

The import time difference between this PR and base is: -1.9 ± 0.1 ms.

Import time breakdown

The following import paths have shrunk:

ddtrace.auto 1.966 ms (0.73%)

ddtrace.bootstrap.sitecustomize 1.288 ms (0.48%)

ddtrace.bootstrap.preload 1.288 ms (0.48%)

ddtrace.internal.remoteconfig.client 0.648 ms (0.24%)

ddtrace 0.678 ms (0.25%)

ddtrace.internal._unpatched 0.032 ms (0.01%)

json 0.032 ms (0.01%)

json.decoder 0.032 ms (0.01%)

re 0.032 ms (0.01%)

enum 0.032 ms (0.01%)

types 0.032 ms (0.01%)