fix: cleanup joserfc.util

Author: lepture

src/joserfc/util.py

@@ -4,7 +4,7 @@
 import struct
 import binascii
 import json
-from .errors import DecodeError
+
 
 def to_bytes(x: Any, charset: str = "utf-8", errors: str = "strict") -> bytes:
     if isinstance(x, bytes):
@@ -21,16 +21,6 @@ def to_str(x: bytes | str, charset: str = "utf-8") -> str:
         return x.decode(charset)
     return x
 
-def __is_urlsafe_b64_encoding_non_canonical(s: bytes) -> bool:
-    p = len(s) % 4 # padding?
-    if p == 0:
-        return False
-    p = 4 - p # number of padding characters
-    if p == 2 and s[-1] in b"AQgw":
-        return False
-    if p == 1 and s[-1] in b"AEIMQUYcgkosw048":
-        return False
-    return True
 
 def urlsafe_b64decode(s: bytes) -> bytes:
     if b"+" in s or b"/" in s: