Update all integrations to use the new Scope API and document it

[antonpirker]

The integrations in the Python SDK still use the Hub and other deprecated API.

Update all the integrations to use the new Scopes API:

• remove any usage of Hub
• remove usages of configure_scope and push_scope and replace with just getting the current/isolation scope or calls to with new_scope().
• document how we replaced the code using the old API with the new one in the migration guide to make it easier for users to upgrade their projects.