Update the enos provider source in build_local

[stevendpclark]

• When running enos scenario validate the following error comes up.

❯ enos scenario validate managed_keys
Scenario: managed_keys [arch:arm64 backend:raft builder:local distro:ubuntu edition:ent seal:awskms]
  Generate: ✅
 Init: ❌

Error: Invalid provider registry host

The host "hashicorp.com" given in in provider source address "hashicorp.com/qti/enos" does not offer a Terraform provider registry.