[MISC] Delete runner password (#912)

* Try to use SSH key

* Set key location

* Allow pubkey auth

* Try to set keys perm

* Try to change the pass

* Try to set pass

* Try to delete pass

Author: dragomirp

spread.yaml

@@ -79,6 +79,8 @@ backends:
       PermitEmptyPasswords yes
       EOF
 
+      sudo passwd -d runner
+
       ADDRESS localhost
     # HACK: spread does not pass environment variables set on runner
     # Manually pass specific environment variables