Merge bitcoin/bitcoin#23723: test: Replace hashlib.new with named constructor

fa1b63c test: Replace hashlib.new with named constructor (MarcoFalke)

Pull request description:

  A small refactor that doesn't matter too much, but it using the named constructor is nice because:
  * It clarifies that it is a built-in function
  * It is (trivially) faster and less code.

ACKs for top commit:
  Zero-1729:
    ACK fa1b63c
  w0xlt:
    ACK fa1b63c

Tree-SHA512: d23dc4552c1e6fc1f90f8272e47e4efcbe727f0b66a6f6a264db8a50ee6cb6d57a2809befcb95fda6725136672268633817a03dd1859f2298d20e3f9e0ca4a7f

Author: MarcoFalke

test/functional/test_framework/messages.py

@@ -64,13 +64,15 @@
 
 WITNESS_SCALE_FACTOR = 4
 
-# Serialization/deserialization tools
+
 def sha256(s):
-    return hashlib.new('sha256', s).digest()
+    return hashlib.sha256(s).digest()
+
 
 def hash256(s):
     return sha256(sha256(s))
 
+
 def ser_compact_size(l):
     r = b""
     if l < 253: