Added

- Introduce usage of `cfg_attr(coverage_nightly)` in order to not consider tests under coverage. #1986

Changed

- deps: bump `esplora-client` to 0.12.1
- deps: bump `bdk_core` to 0.6.1

Fixed

- Esplora `chain_update` returns early with `esplora_client::Error::HeaderHashNotFound` if no point of agreement is found in the local checkpoint #1971