Swift: Test the thinned macOS resource dir

Point at the staging artifact built with the x86_64-only thinning from
semmle-code.  Must be reverted before merging.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 03df685d-b0f4-4920-8c7c-8e70c6c868bf

Author: henrymercer

swift/third_party/load.bzl

@@ -6,6 +6,7 @@ load("//misc/bazel:lfs.bzl", "lfs_archive", "lfs_files")
 
 _override = {
     # these are used to test new artifacts. Must be empty before merging to main
+    "resource-dir-macOS-swift-6.3.3-RELEASE-228.zip": "7c4d3307c8986fb2118bb46d36637fcf82385b8a19153f3656fe5065058fbccb",
 }
 
 _staging_url = "https://github.com/dsp-testing/codeql-swift-artifacts/releases/download/staging-{}/{}"