Are there any test vectors, but only for the new sighash algorithm?

I don't think so.

It just occurred to me that you can reuse the test vectors of BIP341 https://raw.githubusercontent.com/bitcoin-core/qa-assets/main/unit_test_data/script_assets_test.json and to make the unit test, instead of using VerifyScript you could instead construct a CScript out of the script bytes and construct a uint256 hash like this:

Code:

exec_script = CScript(script_bytes.begin(), script_bytes.end());
uint256 hash_exec_script;

And then memcmp() the script hash to its expected value.