Integration tests on Apple Silicon attempt to run under Rosetta and fail

In extensions/ql-vscode, start with run-integration-tests.ts and the npm run integration entry point; then inspect the referenced vscode-test download.ts behavior. Reproduce on an M1 Mac and compare the downloaded Electron binary with the ARM-native path used by the Run and Debug launch configuration. Done means the command launches an ARM-native VS Code without Rosetta and the integration tests pass.

Describe the bug
Running npm run integration from the command line on an M1 Mac leads to the following error:

> vscode-codeql@1.5.9 integration
> node ./out/vscode-tests/run-integration-tests.js no-workspace,minimal-workspace

Found .vscode-test/vscode-1.63.2. Skipping download.
Running integration tests in these directories: no-workspace,minimal-workspace
Next integration test dir: no-workspace
Launch args: --disable-extensions,--disable-gpu
rosetta error: /var/db/oah/279281325309952_279281325309952/79a831ad051c57eb341ad61bf19eea2efece2baf38aaf9eb68316bb0af278da6/Electron.aot: attachment of code signature supplement failed: 1

Exit code:   null
Done

Unexpected exception while running tests: SIGTRAP

Explanation:

• The run-integration-tests.ts test harness downloads a stable copy of VS Code to execute the tests in.
• On Apple Silicon, this downloads an x86 VS Code / Electron binary, even if there is an ARM-native or universal VS Code binary installed.

% file .vscode-test/vscode-1.63.2/Visual Studio Code.app/Contents/MacOS/Electron
.vscode-test/vscode-1.63.2/Visual Studio Code.app/Contents/MacOS/Electron:: Mach-O 64-bit executable x86_64

• I suspect this behaviour originates from vscode-test, specifically https://github.com/microsoft/vscode-test/blob/fd0e599cd8e096f58f226509c6b76c68f502e926/lib/download.ts#L50, because it only accepts darwin as the download platform, without allowing a choice between x86 or ARM.
• This means that the integration tests attempt to run under Rosetta.
• Rosetta fails to launch VS Code due to a code signature mismatch.
• This error doesn't happen when running the integration tests from the Run and Debug UI. This is because the UI test launcher uses the tasks defined in launch.json, which start VS Code directly without going through run-integration-tests.ts, and use the same VS Code binary as the parent instance (which will be ARM native if you installed it on M1).

Version
VS Code 1.63.2
CodeQL for VS Code 1.5.9

To reproduce

• Clone repo on an M1 Mac.
• cd extensions/ql-vscode && npm install && npm run integration
• Observe error.
• Choose Launch Integration Tests from the Run and Debug view in the UI.
• Observe no error.

Expected behavior
npm run integration should download and launch an ARM-native VS Code binary, without using Rosetta, and the tests should pass.

Additional context
Observed by @angelapwen and diagnosed in internal discussion.