Fix mockturtle BUILD file.

  * @fmt library is used, but was not dependent on
  * some superfluous dependencies
  * layering_check was not enabled.

Signed-off-by: Henner Zeller <h.zeller@acm.org>

Author: hzeller

third-party/mockturtle/BUILD

@@ -4,6 +4,12 @@
 load("@rules_cc//cc:cc_library.bzl", "cc_library")
 load("@rules_cc//cc:cc_test.bzl", "cc_test")
 
+package(
+    features = [
+        "layering_check",
+    ],
+)
+
 cc_library(
     name = "mockturtle",
     hdrs = glob(["include/mockturtle/**/*.hpp"]) + glob([
@@ -20,10 +26,8 @@ cc_library(
     ],
     visibility = ["//visibility:public"],
     deps = [
-        "@abseil-cpp//absl/base:core_headers",
         "@abseil-cpp//absl/container:flat_hash_map",
-        "@abseil-cpp//absl/random:random",
-        "@spdlog",
+        "@fmt",
     ],
 )