Fix sympy DeprecationWarning (#2131)

During SBML test case 01288 when handling `true`/`false`:


```
E       sympy.utilities.exceptions.SymPyDeprecationWarning:
E
E       non-Expr objects in a Matrix is deprecated. Matrix represents
E       a mathematical matrix. To represent a container of non-numeric
E       entities, Use a list of lists, TableForm, NumPy array, or some
E       other data structure instead.
E
E       See https://docs.sympy.org/latest/explanation/active-deprecations.html#deprecated-non-expr-in-matrix
E       for details.
E
E       This has been deprecated since SymPy version 1.9. It
E       will be removed in a future version of SymPy.
```

Author: dweindl

python/sdist/amici/sbml_import.py

@@ -18,6 +18,7 @@
 import libsbml as sbml
 import numpy as np
 import sympy as sp
+from sympy.logic.boolalg import BooleanFalse, BooleanTrue
 
 from . import has_clibs
 from .constants import SymbolId
@@ -1047,7 +1048,12 @@ def _process_reactions(self):
                     reaction.getKineticLaw() or sp.Float(0)
                 )
 
-            self.flux_vector[reaction_index] = sym_math
+            self.flux_vector[reaction_index] = sym_math.subs(
+                {
+                    BooleanTrue(): sp.Float(1.0),
+                    BooleanFalse(): sp.Float(0.0),
+                }
+            )
             if any(
                 str(symbol) in reaction_ids
                 for symbol in self.flux_vector[reaction_index].free_symbols