v0.10.0-alpha7

This release adds cog.emit_metric, a predict_time_share metric, and provisional support for setting target concurrency. It also properly records the changes that were already in prod.

What's Changed

• replace requests with httpx and factor out clients by @technillogue in #1574
• implement mp.Connection with async streams by @technillogue in #1640
• omnibus actual concurrency and major refactor by @technillogue in #1530
• fix flaky runner test by @technillogue in #1669
• predict_time_share metric by @technillogue in #1643
• function to emit metrics by @technillogue in #1649
• allow setting both max and target concurrency in cog.yaml by @technillogue in #1672

Full Changelog: v0.10.0-alpha6...v0.10.0-alpha7