Account for change in scipy solver API

`tol=` -> `rtol=` in SciPy 1.12
http://docs.scipy.org/doc/scipy-1.12.0/release/1.12.0-notes.html#deprecated-features

Author: guyer

fipy/solvers/scipy/scipyKrylovSolver.py

@@ -7,10 +7,14 @@
 
 import os
 import warnings
+import scipy
 
 from .scipySolver import ScipySolver
 from fipy.tools import numerix
 from fipy.tools.timer import Timer
+from fipy.tools.version import Version, parse_version
+
+scipy_has_tol = (parse_version(scipy.__version__) < Version("1.12"))
 
 class ScipyKrylovSolver(ScipySolver):
     """
@@ -76,12 +80,17 @@ def _solve_(self, L, x, b):
         self._log.debug("BEGIN solve")
 
         with Timer() as t:
+            if scipy_has_tol:
+                tolerance = dict(tol=rtol)
+            else:
+                tolerance = dict(rtol=rtol)
+
             x, info = self.solveFnc(L, b, x,
-                                    tol=rtol,
                                     atol=self.absolute_tolerance,
                                     maxiter=self.iterations,
                                     M=M,
-                                    callback=self._countIterations)
+                                    callback=self._countIterations,
+                                    **tolerance)
 
         self._log.debug("END solve - {} ns".format(t.elapsed))