Fix SBML import for event-assigned parameters with non-float initial …

…assignments

Currently it is incorrectly assumed that the initial value of an event-assigned parameter
is (convertible to) a float. Therefore, SBML import fails if the initial assignment
contains a symbolic expression that can't be floatified.

Fixes #2149.

python/sdist/amici/sbml_import.py

@@ -1388,7 +1388,7 @@ def _convert_event_assignment_parameter_targets_to_species(self):
             # targets of events.
             self.symbols[SymbolId.SPECIES][parameter_target] = {
                 "name": parameter_def["name"],
-                "init": sp.Float(parameter_def["value"]),
+                "init": sp.sympify(parameter_def["value"]),
                 # 'compartment': None,  # can ignore for amounts
                 "constant": False,
                 "amount": True,