Test revert setuptools pin (#9197)

* Revert setuptools-rust pin

This was a temporary workaround to fix
https://github.com/certbot/certbot/issues/9111, but it looks like the
the issue resolved itself

* Make mypy happy

There was an unused ignore statement, and Validator.certificate was
unnecessarily casting strings as bytes for an X509 digest method.

* Pin setuptools-rust to prevent build-dep hiccups in the future

acme/acme/challenges.py

@@ -472,7 +472,7 @@ class TLSALPN01Response(KeyAuthorizationChallengeResponse):
         # Type ignore needed due to
         # https://github.com/pyca/pyopenssl/issues/730.
         logger.debug('Certificate %s. SANs: %s',
-                     cert.digest('sha256'), names)  # type: ignore[arg-type]
+                     cert.digest('sha256'), names)
         if len(names) != 1 or names[0].lower() != domain.lower():
             return False