add a missing bzl_library dep

Author: aignas

python/private/BUILD.bazel

@@ -197,7 +197,10 @@ bzl_library(
 bzl_library(
     name = "internal_config_repo_bzl",
     srcs = ["internal_config_repo.bzl"],
-    deps = [":bzlmod_enabled_bzl"],
+    deps = [
+        ":bzlmod_enabled_bzl",
+        ":flags_bzl",
+    ],
 )
 
 bzl_library(