anchor test es module error when ubuntu-latest upgraded to nodejs 23+

[poroburu]

investigation:

repo:solana-developers/program-examples path:**/anchor/tests/**test.ts require import

I am investigating a commonjs es module parsing error:

(node:654301) [MODULE_TYPELESS_PACKAGE_JSON] Warning: Module type of file:///home/poroburu/git/solana/program-examples/basics/checking-accounts/anchor/tests/bankrun.test.ts is not specified and it doesn't parse as CommonJS.
Reparsing as ES module because module syntax was detected. This incurs a performance overhead.
To eliminate this warning, add "type": "module" to /home/poroburu/git/solana/program-examples/basics/checking-accounts/anchor/package.json.

Both github action anchor test runs occur on the same commit: 69d6179

https://github.com/solana-developers/program-examples/actions/runs/16843522316
https://github.com/solana-developers/program-examples/actions/runs/16819369110

https://github.com/solana-developers/program-examples/blob/69d61792613b5e2de9723954118336eaef3ec7a1/.github/workflows/anchor.yml

With the assistance of grok, we have identified that ubuntu-latest rolled out an upgrade to node 23 between these runs.

reproduction:

cd basics/checking-accounts/anchor
pnpm i
anchor test

nvm use 22 passes ✅
nvm use 23 fails ❌