Mark rules_pkg as a dev dependency

Author: pcj

MODULE.bazel

@@ -3,4 +3,4 @@ module(name = "protobuf_javascript", version = "4.0.1")
 bazel_dep(name = "abseil-cpp", version = "20250512.1")
 bazel_dep(name = "protobuf", version = "33.0", repo_name = "com_google_protobuf")
 bazel_dep(name = "rules_cc", version = "0.2.15")
-bazel_dep(name = "rules_pkg", version = "1.0.1")
+bazel_dep(name = "rules_pkg", version = "1.0.1", dev_dependency = True)