Revert "Support cross compilation in macOS toolchain builds (#62306)" (#62369)

This reverts commit a36ab6e.

The change to support cross compilation of `docc` in macOS toolchains
is breaking nightly toolchain builds – this will unblock them.

It looks like the `--test-product` option Swift-DocC's build script passes to
SwiftPM is supported when building for multiple architectures but not when
testing. PR toolchain builds don't run tests which is why this wasn't caught
before merging.

Resolves rdar://102908495

Author: ethan-kusters

utils/swift_build_support/swift_build_support/products/swiftdocc.py

@@ -64,13 +64,6 @@ def run_build_script_helper(self, action, host_target, additional_params=[]):
             '--build-dir', self.build_dir,
             '--multiroot-data-file', MULTIROOT_DATA_FILE_PATH,
         ]
-
-        # Pass Cross compile host info
-        if self.has_cross_compile_hosts() and self.is_darwin_host(host_target):
-            helper_cmd += ['--cross-compile-hosts']
-            for cross_compile_host in self.args.cross_compile_hosts:
-                helper_cmd += [cross_compile_host]
-
         if action != 'install':
             helper_cmd.extend([
                 # There might have been a Package.resolved created by other builds