ci: Add local_file resource to test fixture

tests/main.tf

 terraform {
   backend "http" { }
-}
\ No newline at end of file
+}
+
+resource "local_file" "foo" {
+  filename = "${path.module}/foo.bar"
+  content = "bar!"
+  directory_permission = "0755"
+  file_permission = "0755"
+}