chore: Split CI checks into separate jobs

[marandaneto]

💡 Motivation and Context

Split the combined code quality workflow into separate CI jobs so formatting, linting, typing, and package build checks report independently and can run/cancel more cleanly.

Changes:

• Added workflow concurrency to cancel superseded runs for the same PR/ref.
• Split Ruff format, Ruff lint, Mypy, and package build checks into separate jobs.
• Added a reusable local composite action for Python dev environment setup shared by the Ruff and Mypy jobs.
• Added a dedicated package build job that verifies distributions with twine check.

💚 How did you test it?

Reviewed the GitHub Actions workflow configuration and validated the workflow/action YAML parses successfully.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran sampo add to generate a changeset file

[socket-security]

No dependency changes detected. Learn more about Socket for GitHub.

👍 No dependency changes detected in pull request

[github-actions]

posthog-python Compliance Report

Date: 2026-06-11 15:23:05 UTC
Duration: 176119ms

✅ All Tests Passed!

45/45 tests passed

---

Capture Tests

✅ 29/29 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	517ms
Format Validation.Event Has Uuid	✅	1506ms
Format Validation.Event Has Lib Properties	✅	1507ms
Format Validation.Distinct Id Is String	✅	1507ms
Format Validation.Token Is Present	✅	1507ms
Format Validation.Custom Properties Preserved	✅	1506ms
Format Validation.Event Has Timestamp	✅	1507ms
Retry Behavior.Retries On 503	✅	9519ms
Retry Behavior.Does Not Retry On 400	✅	3506ms
Retry Behavior.Does Not Retry On 401	✅	3507ms
Retry Behavior.Respects Retry After Header	✅	9508ms
Retry Behavior.Implements Backoff	✅	23525ms
Retry Behavior.Retries On 500	✅	7508ms
Retry Behavior.Retries On 502	✅	7510ms
Retry Behavior.Retries On 504	✅	7509ms
Retry Behavior.Max Retries Respected	✅	23521ms
Deduplication.Generates Unique Uuids	✅	1500ms
Deduplication.Preserves Uuid On Retry	✅	7513ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	14519ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	7510ms
Deduplication.No Duplicate Events In Batch	✅	1502ms
Deduplication.Different Events Have Different Uuids	✅	1506ms
Compression.Sends Gzip When Enabled	✅	1506ms
Batch Format.Uses Proper Batch Structure	✅	1508ms
Batch Format.Flush With No Events Sends Nothing	✅	1005ms
Batch Format.Multiple Events Batched Together	✅	1504ms
Error Handling.Does Not Retry On 403	✅	3508ms
Error Handling.Does Not Retry On 413	✅	3506ms
Error Handling.Retries On 408	✅	7510ms

Feature_Flags Tests

✅ 16/16 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	1007ms
Request Payload.Flags Request Uses V2 Query Param	✅	1006ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	1007ms
Request Payload.Flags Request Omits Authorization Header	✅	1006ms
Request Payload.Token In Flags Body Matches Init	✅	1007ms
Request Payload.Groups Round Trip	✅	1006ms
Request Payload.Groups Default To Empty Object	✅	1007ms
Request Payload.Person Properties Distinct Id Auto Populated When Caller Omits It	✅	1006ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	1007ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	1006ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	1007ms
Request Lifecycle.No Flags Request On Init Alone	✅	503ms
Request Lifecycle.No Flags Request On Normal Capture	✅	1507ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	1010ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	1003ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	1511ms

[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
.github/workflows/ci.yml:45-67
**Setup steps repeated across three jobs**

The checkout, Python setup, uv install, and dev-dependency install steps are duplicated verbatim in `ruff-format`, `ruff-lint`, and `mypy`. A [composite action](https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-composite-action) (e.g. `.github/actions/setup-python-dev/action.yml`) would centralise this setup so changes only need to be made in one place.

_{Reviews (1): Last reviewed commit: "chore: split CI checks into separate job..." | Re-trigger Greptile}

[greptile-apps]

_{Reviews (2): Last reviewed commit: "address pr review feedback" | Re-trigger Greptile}