Add a test that shows that the local part is returned with Unicode NFC normalization

s + U+0323 + U+0307 normalizes under NFC to U+1E69 (Latin Small Letter S With Dot Below And Dot Above) (https://www.unicode.org/reports/tr15/). We normalize when creating the returned email address info.

Author: JoshData

tests/test_syntax.py

@@ -294,6 +294,16 @@ def test_email_valid(email_input: str, output: ValidatedEmail) -> None:
                 normalized='ιωάννης@εεττ.gr',
             ),
         ),
+        (
+            's\u0323\u0307@nfc.tld',
+            MakeValidatedEmail(
+                local_part='\u1E69',
+                smtputf8=True,
+                ascii_domain='nfc.tld',
+                domain='nfc.tld',
+                normalized='\u1E69@nfc.tld',
+            ),
+        ),
     ],
 )
 def test_email_valid_intl_local_part(email_input: str, output: ValidatedEmail) -> None: