refactor: Annotate null-checked method parameters with @Nullable (#145)

Use this link to re-run the recipe: https://app.moderne.io/recipes/org.openrewrite.staticanalysis.AnnotateNullableParameters?organizationId=ODQ2MGExMTUtNDg0My00N2EwLTgzMGMtNGE1NGExMTBmZDkw

Co-authored-by: Moderne <team@moderne.io>

Author: timtebeek

rewrite-python/src/main/java/org/openrewrite/python/PythonVisitor.java

@@ -553,7 +553,7 @@ public J visitSlice(Py.Slice slice, P p) {
                 right : new JRightPadded<>(t, after, markers);
     }
 
-    public Space visitSpace(Space space, PySpace.Location loc, P p) {
+    public Space visitSpace(@Nullable Space space, PySpace.Location loc, P p) {
         //noinspection ConstantValue
         if (space == Space.EMPTY || space == Space.SINGLE_SPACE || space == null) {
             return space;