Python: Apply suggestions from code review

Co-authored-by: yoff <lerchedahl@gmail.com>

Author: RasmusWL

python/ql/src/semmle/python/security/dataflow/WeakSensitiveDataHashingCustomizations.qll

@@ -140,7 +140,7 @@ module ComputationallyExpensiveHashFunction {
         algorithm instanceof Cryptography::PasswordHashingAlgorithm and
         algorithm.isWeak()
         or
-        algorithm instanceof Cryptography::HashingAlgorithm
+        algorithm instanceof Cryptography::HashingAlgorithm // Note that HashingAlgorithm and PasswordHashingAlgorithm are disjoint
       ) and
       exists(Cryptography::CryptographicOperation operation |
         algorithm = operation.getAlgorithm() and