Update aws-crt to 0.38.4

What's Changed

• CI Fix by @sbSteveK in #622
• Update CRT to 0.38.1 by @sbSteveK in #624
• Reduce CI Flakyness by @sbSteveK in #625
• Fix migration guide rendering by @sfod in #629
• README fixes by @sbSteveK in #631
• Update CRT to v0.38.4 by @sfod in #633
• Use ubuntu 22.04 for releases by @sfod in #635
• AutoTag PR for v1.25.1 by @bretambrose in #636

Full Changelog: v1.25.0...v1.25.1