v0.21.4

Release notes

Fixed

• east install nrfutil-toolchain-manager until now only checked if the nrfutil
  binary is present, but not also if the toolchain-manager package is installed
  inside it. That resulted in situations where the install command would report
  success, however any other east command after it would fail. Now the install
  command checks if the nrfutil binary is present and if the toolchain-manager
  package is installed inside it.