Backport fix for `Problematic` status in `/drop_mempool_tx`

[zone117x]

This was fixed in the Nakamoto pre-release branch: #1790

We're seeing this happen in epoch2.4 so we need to backport the fix to a stable release.

[friedger]

Is there a workaround? Can I clean the mempool manually or something like that?

[zone117x]

@friedger release v7.6.0 includes a fix for this. We currently have it deployed to staging and everything is looking good: https://explorer.hiro.so/?chain=mainnet&api=https://api.stg.hiro.so

We'll be updating our production deployment soon, this issue can be closed