chore(e2e): Set terraform version to 1.5 until issue is addressed (#3797)

.github/workflows/enos-run.yml

@@ -125,6 +125,7 @@ jobs:
           # the terraform wrapper will break Terraform execution in enos because
           # it changes the output to text when we expect it to be JSON.
           terraform_wrapper: false
+          terraform_version: 1.5.7 # QT-623: pin to terraform 1.5.x until a tfjson bug is resolved
       - name: Import GPG key for Boundary pass keystore
         id: import_gpg
         uses: crazy-max/ghaction-import-gpg@72b6676b71ab476b77e676928516f6982eef7a41 # v5.3.0