Resynchronize absl/functional/CMakeLists.txt with BUILD.bazel

overload_test needs some extra dependencies to build when absl::variant
is not an alias for std::variant; these dependencies are listed in
absl/functional/BUILD.bazel but not in absl/functional/CMakeLists.txt.
Copy dependencies from BUILD.bazel to CMakeLists.txt.

PiperOrigin-RevId: 631845552
Change-Id: I63f53323b28aff36530be645b312e94b24475f53

absl/functional/CMakeLists.txt

@@ -129,6 +129,10 @@ absl_cc_test(
   COPTS
   COPTS
     ${ABSL_TEST_COPTS}
     ${ABSL_TEST_COPTS}
   DEPS
   DEPS
+    absl::config
+    absl::overload
+    absl::string_view
     absl::strings
     absl::strings
+    absl::variant
     GTest::gmock_main
     GTest::gmock_main
 )
 )