fix: add provider "github" block with insecure=true for Census GHE TLS

The Census GHE TLS cert is signed by the Census internal CA which is not
present in the CodeBuild container trust store. insecure=true disables
x509 verification so terraform apply can call the GHE API.

providers.tf

@@ -10,3 +10,10 @@ terraform {
     }
   }
 }
+
+# GITHUB_TOKEN and GITHUB_BASE_URL are injected as env vars by the Lambda.
+# insecure = true is required because the Census GHE TLS certificate is signed
+# by the Census internal CA, which is not in the CodeBuild container trust store.
+provider "github" {
+  insecure = true
+}