fix: add versions.tf for pre-commit validate

Add required_providers block so tofu validate works in the module
directory.

modules/prowlarr/versions.tf

@@ -0,0 +1,9 @@
+terraform {
+  required_version = ">= 1.10"
+  required_providers {
+    prowlarr = {
+      source  = "devopsarr/prowlarr"
+      version = ">= 3.2.1"
+    }
+  }
+}