Tracking: remove temporary fork-build Poetry pin workaround after upstream Dockerfile fix

[ewega]

Summary

gh devlake deploy local --source fork now applies a temporary patch to the cloned backend/Dockerfile to pin Poetry (2.2.1) before source builds.

This is a short-term mitigation for upstream breakage in Apache DevLake Docker builds with Python 3.9.

PR #126 extended this workaround to the Azure deployment path (deploy_azure.go) as well.

Upstream Reference

• [Bug][docker] Poetry installation fails without cache due to Python 3.9 incompatibility apache/incubator-devlake#8734

Removal Criteria

• Upstream merges a fix for Poetry installer compatibility in backend/Dockerfile
• The fix is available on the branch/tag we clone/build against

Follow-up Work

• Remove workaround code from cmd/deploy_local.go:
  • applyPoetryPinWorkaround call
  • rewritePoetryInstallLine
• Remove workaround code from cmd/deploy_azure.go (added in fix: apply Poetry pin workaround to Azure fork build path #126):
  • applyPoetryPinWorkaround call and surrounding warning output
• Remove shared constant poetryWorkaroundVersion from cmd/deploy_local.go (used by both paths)
• Remove or adjust any workaround-specific tests in cmd/deploy_local_test.go
• Re-run go build ./..., go test ./..., go vet ./...

Notes

Current behavior is non-fatal: if the patch cannot be applied, deploy continues and warns in terminal output.