Swift: fix local build on ARM macOS

As pointed out in bazelbuild/bazel#21768,
bazel 7 moved multi-arch macOS toolchain support to `apple_support`,
so building Swift (which must target `x86_64` for now) was broken.
Internally in the codeql CLI we were unaffected as we use a custom
bundled toolchain.

This fixes building from this repository.

Author: redsun82

.bazelrc

@@ -11,7 +11,7 @@ common --override_module=semmle_code=%workspace%/misc/bazel/semmle_code_stub
 build --repo_env=CC=clang --repo_env=CXX=clang++
 
 build:linux --cxxopt=-std=c++20
-build:macos --cxxopt=-std=c++20 --cpu=darwin_x86_64
+build:macos --cxxopt=-std=c++20 --platforms=@apple_support//platforms:macos_x86_64
 build:windows --cxxopt=/std:c++20 --cxxopt=/Zc:preprocessor
 
 try-import %workspace%/local.bazelrc

MODULE.bazel

@@ -12,7 +12,7 @@ local_path_override(
 )
 
 # see https://registry.bazel.build/ for a list of available packages
-
+bazel_dep(name = "apple_support", version = "1.14.0")
 bazel_dep(name = "platforms", version = "0.0.8")
 bazel_dep(name = "rules_pkg", version = "0.9.1")
 bazel_dep(name = "rules_nodejs", version = "6.0.3")