docs: Add explanation to migration docs why RewriteFrames shouldn't be used

[lforst]

We see people having issues with debug IDs because they're still using the RewriteFrames integration from previous setups.

This PR adds a section to the migration docs clarifying that it should be removed when using debug IDs.

[mydea]

😬 it is not ideal that this is needed... is there a way we could automatically disable it if we detect debug ids are used? 🤔 but for now makes sense to add this at least.

[lforst]

😬 it is not ideal that this is needed... is there a way we could automatically disable it if we detect debug ids are used? 🤔 but for now makes sense to add this at least.

Hard agree. I tried to get this through on the processing side of things in the backend by putting the debug ID directly on the stack frame objects. That would prevent any values from getting out of sync but it would have big implications on the processing pipeline in the backend.

@mitsuhiko brought up that we could just put the debug IDs on the individual frame objects and move them to the debug meta field right before sending. I am gonna try that before I merge this PR.

[lforst]

PR became redundant because we fixed this in the SDK getsentry/sentry-javascript#8347