* MSPF-445: Add Step and correct paths for step calls in keyring.py
* MSPF-445: Move installation of Step to base image and remove binary from holmes
* MSPF-445: Remove party_migration_script due to being useless and not being OTP 21 compliant
* MSPF-445: Remove last mention of party_migration_script
* Bump submodule versions
* Refactor build stage a bit
* Add observer-cli to the mix
* Separate build artifacts from repo scripts
* Bump to rbkmoney/image-build@9d4d703