mypy fix for integer type infinity

spacy/pipeline/span_finder.py

@@ -148,6 +148,11 @@ def span_finder_score(
     return scores
 
 
+class _MaxInt(int):
+    def __le__(self, other):
+        return False
+
+
 class SpanFinder(TrainablePipe):
     """Pipeline that learns span boundaries"""
 
@@ -184,15 +189,16 @@ class SpanFinder(TrainablePipe):
         self.vocab = nlp.vocab
         self.threshold = threshold
         if max_length is None:
-            max_length = float("inf")
+            max_length = _MaxInt()
         if min_length is None:
             min_length = 1
+
+        self.min_length = min_length
+        self.max_length = max_length
         if max_length < 1 or min_length < 1:
             raise ValueError(
                 Errors.E1052.format(min_length=min_length, max_length=max_length)
             )
-        self.max_length = max_length
-        self.min_length = min_length
         self.predicted_key = predicted_key
         self.training_key = training_key
         self.model = model