Add build dependencies for arenaz_sampler_test.

We are seeing some GHA breakages; they may have been caused by
https://github.com/protocolbuffers/protobuf/pull/20052 as the Bazel build rules
couldn't find the necessary headers.

PiperOrigin-RevId: 721910271

python/build_targets.bzl

@@ -150,6 +150,7 @@ def build_targets(name):
             "@com_google_absl//absl/log:absl_check",
             "@com_google_absl//absl/log:absl_log",
             "@com_google_absl//absl/status",
+            "@com_google_absl//absl/status:statusor",
             "@com_google_absl//absl/strings",
         ] + select({
             "//conditions:default": [],

src/google/protobuf/BUILD.bazel

@@ -1385,9 +1385,15 @@ cc_test(
     srcs = ["arenaz_sampler_test.cc"],
     deps = [
         ":arena",
+        ":arena_allocation_policy",
         ":port",
         ":protobuf",
         "//src/google/protobuf/stubs",
+        "@com_google_absl//absl/log:absl_check",
+        "@com_google_absl//absl/numeric:bits",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/synchronization",
+        "@com_google_absl//absl/time",
         "@com_google_googletest//:gtest",
         "@com_google_googletest//:gtest_main",
     ],