test-mongodb-runner.sh:
- Fix connect_mongodb exit code propagation: bash disables set -e inside
  functions called from an if condition, causing mongosh failures to be
  swallowed. Use || result=$? to capture the real exit code.
- Add --eval-cmd flag so callers can supply a custom MongoDB command.
- Fix auth enforcement check: use db.adminCommand({listDatabases:1}),
  which requires authentication even without an explicit auth source,
  rather than ping which succeeds unauthenticated on some topologies.
- Pass --auth credentials when connecting to auth-enabled standalone
  and sharded cluster servers.

mongodb_runner.py:
- Replace "npx -y mongodb-runner@^6.7.1" with a local npm install that
  pins @mongodb-js/oidc-mock-provider to 0.13.7. npx does not support
  npm overrides, and oidc-mock-provider 0.13.8+ pulled in yargs@18
  (ESM-only), which cannot be require()'d on Node 16 (ERR_REQUIRE_ESM).
- Add --experimental-global-webcrypto to NODE_OPTIONS for Node 16-18.
  The crypto global was not exposed until Node 19; the mongodb driver
  uses it at startup. The flag was removed in Node 22, so it is only
  added when node_major < 19.
- Fix Windows subprocess execution: Python cannot CreateProcess a .cmd
  file without shell=True. Use shell=True and pass the command as a
  string on win32 for both the npm install and the mongodb-runner Popen.

test-install-binaries.sh:
- Replace "npx -y mongodb-runner --help" with the same npm install +
  overrides approach used in mongodb_runner.py.
- Source init-node-and-npm-env.sh after install-node.sh so the freshly
  installed Node is on PATH (running install-node.sh as a subprocess
  does not propagate its PATH changes to the caller).
- Use a subshell + cd for npm install instead of --prefix to avoid
  MSYS2/Cygwin Unix-path translation issues when npm-cli.js runs as a
  Windows process.
- Invoke node runner.js directly instead of the .bin/ POSIX shim.
  The shim can have CRLF line endings on Windows, making the shebang
  unresolvable and causing bash to return exit 127.

- mongodb_runner.py: raise RuntimeError if shutil.which("npm") returns
  None rather than passing None to subprocess, which would raise a
  confusing TypeError or attempt to run a literal "None" command.
- test-install-binaries.sh: add trap to remove MR_INSTALL_DIR on EXIT
  so the temp directory is cleaned up even if the script fails.