* Reduce Nim 1.6 compiler warnings/hints for Fluffy and Nimbus proxy
Mostly raises Defect removals, TaintedString removal and some
unnecessary imports.
Also updating the copyright years alongside.
* Further reduce Nim 1.6 compiler warnings/hints for Nimbus
* Remove unused import of config to avoid select_backend db import
- Importing nimbus-eth1 config.nim causes import of select_backend
which will default cause an import of kvstore_rocksdb and thus a
require rocksdb. Remove unused one to avoid rocksdb dependency
for Fluffy.
- Remove some whitespace in bridge_client (to make fluffy CI
trigger for sure).
* Use specific cache keys for fluffy CI workflow
* Disable Fluffy CI reproducibility test
Kim De Mey
KonradStaniec