remove rationale comment for OpenSSL SHA-1

In this commit, we move the rationale for using OpenSSL-based SHA-1
instead of its HACL* implementation from the code to this note.

HACL*-based SHA-1 is 2x faster than its OpenSSL implementation for
creating the hash object via `h = sha1(..., usedforsecurity=False)`
but `h.digest()` is almost 3x slower.

Unlike HACL* MD5, HACL*-based SHA-1 is slower than its OpenSSL-based
implementation, whence the choice of `hashlib.sha1` over `_sha1.sha1`.

Author: picnixz

Lib/uuid.py

@@ -747,8 +747,6 @@ def uuid5(namespace, name):
     """Generate a UUID from the SHA-1 hash of a namespace UUID and a name."""
     if isinstance(name, str):
         name = bytes(name, "utf-8")
-    # OpenSSL-based SHA-1 is slightly faster than its HACL* version,
-    # and 'import X; X.Y' is slightly faster than 'from X import Y'.
     import hashlib
     h = hashlib.sha1(namespace.bytes + name, usedforsecurity=False)
     int_uuid_5 = int.from_bytes(h.digest()[:16])