Remove custom implementation of percent_encode

We can rely on the standard library starting from Python 3.7.

Author: pquentin

elastic_transport/client_utils.py

@@ -21,7 +21,7 @@
 import re
 from platform import python_version
 from typing import Optional, Tuple, TypeVar, Union
-from urllib.parse import quote as _quote
+from urllib.parse import quote as percent_encode
 
 from urllib3.exceptions import LocationParseError
 from urllib3.util import parse_url
@@ -149,25 +149,6 @@ def to_bytes(
     return value
 
 
-# Python 3.7 added '~' to the safe list for urllib.parse.quote()
-_QUOTE_ALWAYS_SAFE = frozenset(
-    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_.-~"
-)
-
-
-def percent_encode(
-    string: Union[bytes, str],
-    safe: str = "/",
-    encoding: Optional[str] = None,
-    errors: Optional[str] = None,
-) -> str:
-    """Percent-encodes a string so it can be used in an HTTP request target"""
-    # Redefines 'urllib.parse.quote()' to always have the '~' character
-    # within the 'ALWAYS_SAFE' list. The character was added in Python 3.7
-    safe = "".join(_QUOTE_ALWAYS_SAFE.union(set(safe)))
-    return _quote(string, safe, encoding=encoding, errors=errors)  # type: ignore[arg-type]
-
-
 def basic_auth_to_header(basic_auth: Tuple[str, str]) -> str:
     """Converts a 2-tuple into a 'Basic' HTTP Authorization header"""
     if (