Release 0.21.4

What's Changed

• fix: distinguish remote dev environments from known hosts by @rvanasa in #830
• feat: release automation changes by @krpeacock in #832
• chore: updating package-lock by @krpeacock in #831
• fix: export partial identity from index of @dfinity/identity by @krpeacock in #833
• fix: edit to the post-release script by @krpeacock in #834
• fix: edit to the post-release script by @krpeacock in #836

Full Changelog: v0.21.2...v0.21.4