fix: do note check stainless api key during release creation (#813)

Author: ms-jpq

bin/check-release-environment

@@ -2,10 +2,6 @@
 
 errors=()
 
-if [ -z "${STAINLESS_API_KEY}" ]; then
-  errors+=("The STAINLESS_API_KEY secret has not been set. Please contact Stainless for an API key & set it in your organization secrets on GitHub.")
-fi
-
 if [ -z "${GEM_HOST_API_KEY}" ]; then
   errors+=("The GEM_HOST_API_KEY secret has not been set. Please set it in either this repository's secrets or your organization secrets")
 fi