pg_regress: Disable autoruns for cmd.exe on Windows
This is similar to
9886744a361b, to prevent the execution of other
programs due to autorun configurations which could influence the
postmaster startup.
Like the other change, no backpatch is done.
Discussion: https://postgr.es/m/
20230922.161551.
320043332510268554.horikyota.ntt@gmail.com