fix(vscode): move test user-data dir out of the workspace

macOS caps Unix domain socket paths at 103 chars. The default user-data
dir (<workspace>/.vscode-test/user-data) puts VS Code's main socket well
past that on CI runners, so the host died with:

  listen EINVAL: invalid argument .../user-data/1.13-main.sock

Point --user-data-dir at os.tmpdir() instead, which keeps the socket
short on every platform. test-electron skips its own default when the
flag is already present.

Author: blazejkustra

packages/vscode-client/.vscode-test.mjs

@@ -1,5 +1,14 @@
 import { defineConfig } from '@vscode/test-cli';
+import * as os from 'node:os';
+import * as path from 'node:path';
+
+// Keep the user-data dir out of the workspace. VS Code opens a Unix domain
+// socket inside it, and macOS caps those paths at 103 chars — the default
+// (<workspace>/.vscode-test/user-data) overflows on CI runners, which fail
+// with `listen EINVAL: invalid argument .../1.13-main.sock`.
+const userDataDir = path.join(os.tmpdir(), 'rcm-vscode-test');
 
 export default defineConfig({
 	files: 'out/test/**/*.test.js',
+	launchArgs: [`--user-data-dir=${userDataDir}`],
 });