Unable to sideload Unified Manifest due to 429 error

[JackSteel97]

Expected behavior

Expect that running office-addin-debugging start manifest.json command should sideload and start the associated add-in.

Current behavior

Sideloading fails with a 429 error (full error message below). This has been happening for over a week now, all unified manifests are impacted even brand new scaffolded projects.

--Error sideloading!--
Error: Error: Command failed: npx -p @microsoft/m365agentstoolkit-cli atk install --file-path "C:\Users\JACKST~1\AppData\Local\Temp\manifest.zip" --interactive false
(×) Error: m365.InternalError: Request failed with status code 429 (tracingId: ) undefined: undefined

STDERR:
(×) Error: m365.InternalError: Request failed with status code 429 (tracingId: ) undefined: undefined

Error: Unable to start debugging.
Error: Unable to sideload the Office Add-in.
Error: Command failed: npx -p @microsoft/m365agentstoolkit-cli atk install --file-path "C:\Users\JACKST~1\AppData\Local\Temp\manifest.zip" --interactive false       
(×) Error: m365.InternalError: Request failed with status code 429 (tracingId: ) undefined: undefined

Steps to Reproduce

Please provide detailed steps for reproducing the issue.

1. Create a unified manifest Office Addin project
2. Use office-addin-debugging to attempt to start the project locally
3. Observe the error

Context

First noticed on office-addin-debugging version 6.0.4 but have reproduced on latest version 6.0.6 too.

This entirely blocks debugging unified manifest apps. An equivalent XML manifest for the same project does not suffer this issue and can sideload and launch as expected.

Possibly related to: OfficeDev/microsoft-365-agents-toolkit#14684 (comment)

Failure Logs

Please include any relevant log snippets, screenshots or code samples here.

[DDJensMadsen]

See OfficeDev/office-js#6223