chore: platform v1.0.0-dev.12 with Core 21

[shumkov]

Issue being fixed or feature implemented

This version of core contains a bug so we want to release a platform compatible with current testnet version for further investigation

What was done?

• Updated dashd-rpc to compatible version

How Has This Been Tested?

Breaking Changes

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have added "!" to the title and described breaking changes in the corresponding section if my code contains any
• I have made corresponding changes to the documentation if needed

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone