Pass `testonly` and `visibility` to the alias. (#83)

build_defs.bzl

diff --git a/build_defs.bzl b/build_defs.bzl
index 503ce33..d53a640 100644
--- a/build_defs.bzl
+++ b/build_defs.bzl
@@ -68,7 +68,8 @@
         name = name + "_copy_so_to_pyd",
         src = name + ".so",
         out = name + ".pyd",
-        testonly = kwargs.get("testonly")
+        testonly = kwargs.get("testonly"),
+        visibility = kwargs.get("visibility"),
     )
 
     native.alias(
@@ -77,6 +78,8 @@
             "@platforms//os:windows": name + ".pyd",
             "//conditions:default": name + ".so",
         }),
+        testonly = kwargs.get("testonly"),
+        visibility = kwargs.get("visibility"),
     )
 
 # Builds a pybind11 compatible library. This can be linked to a pybind_extension.