Make desired output order tuple for LRU cache to hash

Discovered by Thomas K

src/calng/base_kernel_runner.py

@@ -253,7 +253,7 @@ class BaseKernelRunner:
                 self._output_transpose = None
             else:
                 self._output_transpose = misc.transpose_order(
-                    ("f", "ss", "fs"), order.split("-")
+                    ("f", "ss", "fs"), tuple(order.split("-"))
                 )
 
         if config.has("corrections.badPixels.maskingValue"):