Make Chris and Anton codeowners only of '.proto' files from 'supervisor-api'

Author: felladrin

.github/CODEOWNERS

@@ -64,7 +64,7 @@
 /components/registry-facade @gitpod-io/engineering-workspace
 /components/server @gitpod-io/engineering-webapp
 /components/service-waiter @gitpod-io/engineering-webapp
-/components/supervisor-api @csweichel @akosyakov
+/components/supervisor-api/*.proto @csweichel @akosyakov
 /components/supervisor @gitpod-io/engineering-ide
 /components/usage @gitpod-io/engineering-webapp
 /components/usage-api @gitpod-io/engineering-webapp