remove the is_jacobian_term_used logic in the linear algebra (#1502)

this was wrong, but turns out, it had no effect because of a bug
in the logic of the is_jacobian_term_used.  That issue is also
fixed here, and the function is kept for use in the future.

note: nets with one species that was not evolved will see a change here.

Author: zingale

networks/rhs.H

@@ -263,7 +263,7 @@ constexpr int is_jacobian_term_used ()
             }
         }
 
-        if (is_spec_1_used || is_spec_2_used) {
+        if (is_spec_1_used && is_spec_2_used) {
             term_is_used = 1;
         }
     });
@@ -289,9 +289,7 @@ void dgesl (RArray2D& a1, RArray1D& b1)
         {
             constexpr int j = n2;
 
-            if (is_jacobian_term_used<j, k>()) {
-                b(j) += t * a(j,k);
-            }
+            b(j) += t * a(j,k);
         });
     });
 
@@ -305,9 +303,7 @@ void dgesl (RArray2D& a1, RArray1D& b1)
 
         constexpr_for<0, k>([&] (auto j)
         {
-            if (is_jacobian_term_used<j, k>()) {
-                b(j) += t * a(j,k);
-            }
+            b(j) += t * a(j,k);
         });
     });
 }
@@ -329,9 +325,7 @@ void dgefa (RArray2D& a1)
         {
             [[maybe_unused]] constexpr int j = n2;
 
-            if (is_jacobian_term_used<j, k>()) {
-                a(j,k) *= t;
-            }
+            a(j,k) *= t;
         });
 
         // row elimination with column indexing
@@ -344,9 +338,7 @@ void dgefa (RArray2D& a1)
             {
                 [[maybe_unused]] constexpr int i = n3;
 
-                if constexpr (is_jacobian_term_used<i, k>()) {
-                    a(i,j) += t * a(i,k);
-                }
+                a(i,j) += t * a(i,k);
             });
         });
     });

unit_test/burn_cell/ci-benchmarks/chamulak_VODE_unit_test.out

@@ -1,4 +1,5 @@
-AMReX (23.07-7-g88f03408f18a-dirty) initialized
+Initializing AMReX (24.02-30-g2ecafcff4013)...
+AMReX (24.02-30-g2ecafcff4013) initialized
 starting the single zone burn...
 Maximum Time (s): 0.01585
 State Density (g/cm^3): 1000000000
@@ -12,21 +13,21 @@ RHS at t = 0
    ash 0.01230280576
 ------------------------------------
 successful? 1
- - Hnuc = 5.274803093e+17
- - added e = 8.360562902e+15
- - final T = 1433512646
+ - Hnuc = 5.277406316e+17
+ - added e = 8.364689011e+15
+ - final T = 1433713029
 ------------------------------------
 e initial = 1.253426044e+18
-e final =   1.261786607e+18
+e final =   1.261790733e+18
 ------------------------------------
 new mass fractions: 
-C12 0.9658063217
-O16 9.999999766e-31
-ash 0.03419367826
+C12 0.9657894807
+O16 1e-30
+ash 0.03421051932
 ------------------------------------
 species creation rates: 
-omegadot(C12): -2.157329859
-omegadot(O16): -1.476105976e-36
-omegadot(ash): 2.157329859
+omegadot(C12): -2.158392386
+omegadot(O16): 3.315374916e-44
+omegadot(ash): 2.158392386
 number of steps taken: 381
-AMReX (23.07-7-g88f03408f18a-dirty) finalized
+AMReX (24.02-30-g2ecafcff4013) finalized