[workspace] Adjust apple_support for Bazel 7 compatibility (RobotLoco…

…motion#21116)

This re-applies f2187b3 (by reverting the 5a35be0 revert).

For macOS users building from source, Bazel 7 now requires a snippet
to be added directly to WORKSPACE (not our default.bzl), or to the
MODULE.bazel. Downstream projects using drake_bazel_external on macOS
will need to mimic this same change (or similar), per instructions at
https://github.com/bazelbuild/apple_support#toolchain-setup.

WORKSPACE

@@ -7,6 +7,10 @@ load("//tools/workspace:default.bzl", "add_default_workspace")
 
 add_default_workspace()
 
+load("@build_bazel_apple_support//crosstool:setup.bzl", "apple_cc_configure")
+
+apple_cc_configure()
+
 # Add some special heuristic logic for using CLion with Drake.
 load("//tools/clion:repository.bzl", "drake_clion_environment")
 

cmake/WORKSPACE.in

@@ -22,3 +22,7 @@ _BAZEL_WORKSPACE_EXCLUDES = split_cmake_list("@BAZEL_WORKSPACE_EXCLUDES@")
 add_default_workspace(
     repository_excludes = ["python"] + _BAZEL_WORKSPACE_EXCLUDES,
 )
+
+load("@build_bazel_apple_support//crosstool:setup.bzl", "apple_cc_configure")
+
+apple_cc_configure()