chore(enos): Default to use OSS edition (#3035)

There was an update to the build scripts to detect what edition of boundary is being built so that it knows which version of the UI to grab. However, this affected instances when building boundary on an architecture that is not the same as the host (in this case, we're building a linux/amd64 version on a mac). When the scripts try to use the built CLI to get the edition, it threw an `exec format error`.

enos/modules/build_local/main.tf

@@ -17,6 +17,10 @@ variable "build_target" {
   default = "build-ui build"
 }
 
+variable "edition" {
+  default = "oss"
+}
+
 resource "enos_local_exec" "build" {
   environment = {
     "GOOS"          = "linux",
@@ -24,6 +28,7 @@ resource "enos_local_exec" "build" {
     "CGO_ENABLED"   = 0,
     "ARTIFACT_PATH" = var.path
     "BUILD_TARGET"  = var.build_target
+    "EDITION"       = var.edition
   }
   scripts = ["${path.module}/templates/build.sh"]
 }