fix(fluids): Update tests for fixed ts_type alpha

The startup logic for `ts_type: alpha` was fixed in petsc/petsc!7816, so
the reference solutions needed to be fixed as well.

Author: jrwrigh

examples/fluids/problems/newtonian.c

@@ -129,7 +129,7 @@ static PetscErrorCode UnitTests_Newtonian(User user, NewtonianIdealGasContext ga
                                  -rho_div_p};
 
   {
-    CeedScalar rtol = 20 * CEED_EPSILON;
+    CeedScalar rtol = 40 * CEED_EPSILON;
 
     PetscCall(TestState(STATEVAR_PRIMITIVE, STATEVAR_CONSERVATIVE, gas, Y0, rtol, rtol, rtol));
     PetscCall(TestState(STATEVAR_PRIMITIVE, STATEVAR_ENTROPY, gas, Y0, rtol, rtol, rtol));