Tridiagonal Solve: Fix dtype inference

Scipy helper doesn't have special handling for ipiv int32 variable, and always assumes it must be cast to a float64

Author: ricardoV94

pytensor/tensor/_linalg/solve/tridiagonal.py

@@ -146,9 +146,8 @@ def make_node(self, dl, d, du, du2, ipiv, b):
                 n = nb
 
         dummy_arrays = [
-            np.zeros((), dtype=inp.type.dtype) for inp in (dl, d, du, du2, ipiv)
+            np.zeros((), dtype=inp.type.dtype) for inp in (dl, d, du, du2, b)
         ]
-        # Seems to always be float64?
         out_dtype = get_lapack_funcs("gttrs", dummy_arrays).dtype
         if self.b_ndim == 1:
             output_shape = (n,)