Add migration step for the socket.io update on Theia 1.23

[drochgenius]

What it does

Add new migration step in the Migration Guide related to the socket.io update on Theia 1.23.

How to test

Nothing to test, it's a documentation update.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[paul-marechal]

Thanks!

[paul-marechal]

Ah, could you make sure to sign the Eclipse ECA? Your commit must be authored with the same email registered there.

https://accounts.eclipse.org/user/eca

[drochgenius]

Hi @paul-marechal , I have signed the Eclipse ECA.

[paul-marechal]

The ECA check keeps failing even after revalidation. I don't know what email you used when signing, but the Git commit was made using [email protected]. Make sure you used the same email while both signing the ECA and authoring commits.

[drochgenius]

I have signed the agreement, but somehow it doesn't want to clear the check.