Release v1.29.0 Checklist

[MrAlias]

• Complete milestones:
  • https://github.com/open-telemetry/opentelemetry-go-contrib/milestone/22
  • https://github.com/open-telemetry/opentelemetry-go/milestone/61
• Update contrib codebase to support changes about to be released (use a git sha version)
• Pre-release: #5732
• Tag
• Release
• Check examples
• Sync with Contrib
• Release contrib: open-telemetry/opentelemetry-go-contrib#6042
• Sync website docs
• Close the milestones

[MrAlias]

Done