Address review comments

- Add darwin/x64 case to linked bundle tests and disambiguate the
  parametrized test title by platform/arch
- Reword CHANGELOG entry to clarify the CLI supports Linux Arm64
- Add a dedicated Linux Arm64 end-to-end PR check on ubuntu-24.04-arm

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 308c78bb-53a3-4877-a373-70fab87543f1

src/setup-codeql.test.ts

@@ -139,6 +139,13 @@ const LINKED_BUNDLE_TEST_CASES = [
     expectedBundleName: "codeql-bundle-osx64.tar.zst",
     expectedCompressionMethod: "zstd",
   },
+  {
+    platform: "darwin",
+    arch: "x64",
+    tarSupportsZstd: true,
+    expectedBundleName: "codeql-bundle-osx64.tar.zst",
+    expectedCompressionMethod: "zstd",
+  },
   {
     platform: "win32",
     arch: "x64",
@@ -163,7 +170,7 @@ for (const {
   expectedCompressionMethod,
 } of LINKED_BUNDLE_TEST_CASES) {
   test.serial(
-    `getCodeQLSource selects ${expectedBundleName} for linked tools`,
+    `getCodeQLSource selects ${expectedBundleName} for linked tools on ${platform}/${arch}`,
     async (t) => {
       const features = createFeatures([]);
       sinon.stub(process, "platform").value(platform);