chore(dev): let more tools know that we use 120 character per line

[apiarian-datadog]

Some instances of flake8 expect to find their max-line-length config in setup.cfg.

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:

setup.cfg                                                               @DataDog/python-guild

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: aleksandr.pasechnik/tweak-setup-cfg
Commit report: 757eefe
Test service: dd-trace-py

✅ 0 Failed, 141107 Passed, 1669 Skipped, 8h 36m 23.79s Total duration (17.61s time saved)

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-08-26 14:31:54

Comparing candidate commit 757eefe in PR branch aleksandr.pasechnik/tweak-setup-cfg with baseline commit ee75b12 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 353 metrics, 47 unstable metrics.