This PR adds possibility to set BUILD_OPTIONS to the "Srtool Build" step
in the release pipeline while building runtimes.

Colses: https://github.com/paritytech/release-engineering/issues/213

---------

Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: EgorPopelyaev <EgorPopelyaev@users.noreply.github.com>