Checks for active workers when deploying

[jeanluciano]

This PR adds code to check if a work pool has active workers when deploying a flow in order to not display irrelevant informantion to users with an existing setup. This check is added to the various methods for deploying a flow.
closes #15513

Checklist

• This pull request references any related issue by including "closes <link to issue>"
  • If no issue exists and your change is not a small fix, please create an issue first.
• If this pull request adds new functionality, it includes unit tests that cover the changes
• If this pull request removes docs files, it includes redirect settings in mint.json.
• If this pull request adds functions or classes, it includes helpful docstrings.

[codspeed-hq]

CodSpeed Performance Report

Merging #15632 will not alter performance

_{Comparing jean/oss-5686-do-not-provide-worker-setup-instructions-in-deployment-to (6387a1b) with main (b7b79a4)}

Summary

✅ 3 untouched benchmarks

[desertaxle]

In addition to my stylistic comments, can you please add coverage for the changes to the prefect deploy CLI and flow.deploy? Also, looks like there's a .swp file that snuck into this PR.