We have 3 functions for which have 4-way batched and scalar variants:

• mld_poly_uniform_gamma1 + mld_poly_uniform_gamma1_4x
• mld_poly_uniform_eta + mld_poly_uniform_eta_4x
• mld_poly_uniform + mld_poly_uniform_4x

We should add unit tests making sure these functions indeed produce the same outputs.
This is particularly important for mld_poly_uniform_eta as there the scalar version is only present if MLD_CONFIG_SERIAL_FIPS202_ONLY is set.