Add regex check to error expectation

[samshull]

Checklist

• make -j8 test (UNIX), or vcbuild test nosign (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Description of change

Add regex check to error expectation that matches the expected error message.

[mscdex]

Please follow the commit message guidelines here.

[samshull]

@mscdex updated explanation

[samshull]

Closed in favor of #10038