Inline `MetaData` ordering when dumping to yaml

[kenodegard]

Description

Simplified conda_build.render.output_yaml to avoid the most costly MetaData.copy and to eliminate the need for special customizations of the yaml engine.

Checklist - did you ...

• [x] Add a file to the news directory (using the template) for the next release's release notes?
• [ ] ~Add / update necessary tests?~
• [ ] ~Add / update outdated documentation?~

[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #5282 will not alter performance

_{Comparing kenodegard:remove-unicode (4d5a663) with main (b7ea405)}

Summary

✅ 3 untouched benchmarks