[RI] Change the fuzz factor to 2

When a fuzz factor of 3 results in an incorrect patch application, the
final interdiff output is harder to review than when the fuzz factor is 2.
This is especially the case because it's common for rejected hunks from
both files to appear back-to-back, making the rejected hunks easy to
review.

Turn down the fuzz factor to the default of 2 to avoid results that are
very confusing.

Author: kerneltoast

run_interdiff.py

@@ -89,7 +89,7 @@ def run_interdiff(repo, backport_sha, upstream_sha, interdiff_path):
             up_path = up.name
 
         interdiff_result = subprocess.run(
-            [interdiff_path, "--fuzzy=3", bp_path, up_path], text=True, capture_output=True, check=False
+            [interdiff_path, "--fuzzy", bp_path, up_path], text=True, capture_output=True, check=False
         )
 
         # Check for interdiff errors (non-zero return code other than 1)