Update ownership of bitwarden-crypto (#311)

Assigns codeownership of crate/bitwarden-crypto to platform, km and
architecture during the handover period. Ideally we want two of the
teams to review changes, one focusing on domain expertise and the other
on idiomatic rust and code quality.

Author: Hinton

.github/CODEOWNERS

@@ -9,6 +9,9 @@
 
 crates/bitwarden-vault/** @bitwarden/team-vault-dev @bitwarden/team-platform-dev
 
+# Temporarily owned by multiple teams
+/crates/bitwarden-crypto/ @bitwarden/team-platform-dev @bitwarden/dept-architecture @bitwarden/team-key-management-dev
+
 # BRE for publish workflow changes
 .github/workflows/publish-*.yml @bitwarden/dept-bre
 .github/workflows/release-rust-crates.yml @bitwarden/dept-bre