Fix bazel build //:tarfile

The packaging target wasn't public and it failed to be referenced
by the top-level alias, mirroring the earlier //:install fix.

Signed-off-by: Matt Liberty <mliberty@precisioninno.com>

Author: maliberty

packaging/BUILD.bazel

@@ -16,5 +16,8 @@ pkg_tar(
     srcs = ["//:openroad"],
     include_runfiles = True,
     package_file_name = "openroad.tar",
-    visibility = ["//test:__subpackages__"],
+    visibility = [
+        "//:__pkg__",
+        "//test:__subpackages__",
+    ],
 )