Pin code scanning pack integration fixture

Keep the code scanning resolution test compatible with all supported CLI
versions while asserting that production still requests the latest language
pack.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot-Session: de15564b-31a3-459b-9d6b-483ebc280d76

Author: cklin

extensions/ql-vscode/test/vscode-tests/cli-integration/variant-analysis/code-scanning-pack.test.ts

@@ -17,12 +17,25 @@ describe("Code Scanning pack", () => {
   });
 
   it("should download pack for correct language and identify problem queries", async () => {
+    // Pin the registry fixture because this test covers query resolution, not pack manifest compatibility.
+    // Remove the pin once every supported CLI can download the latest query pack.
+    const packDownload = cli.packDownload.bind(cli);
+    const packDownloadSpy = jest
+      .spyOn(cli, "packDownload")
+      .mockImplementation((_packs, token) =>
+        packDownload(["codeql/javascript-queries@2.4.2"], token),
+      );
+
     const pack = await resolveCodeScanningQueryPack(
       app.logger,
       cli,
       QueryLanguage.Javascript,
       new CancellationTokenSource().token,
     );
+    expect(packDownloadSpy).toHaveBeenCalledWith(
+      ["codeql/javascript-queries"],
+      expect.anything(),
+    );
     // Should include queries. Just check that at least one known query exists.
     // It doesn't particularly matter which query we check for.
     expect(