cleanup: delete distribs attribute from java_proto_library()

PiperOrigin-RevId: 682114879

bazel/private/bazel_java_proto_library_rule.bzl

@@ -154,7 +154,6 @@ rules to generate Java code for.
         ),
         # buildifier: disable=attr-license (calling attr.license())
         "licenses": attr.license() if hasattr(attr, "license") else attr.string_list(),
-        "distribs": attr.string_list(),
     } | toolchains.if_legacy_toolchain({
         "_aspect_java_proto_toolchain": attr.label(
             default = configuration_field(fragment = "proto", name = "proto_toolchain_for_java"),