Avoid unnecessary indirection

Since there's not equivalent of get_isolated_environment_bin_path for
the distutils backend, the additional declaretion in the sysconfig
backend is unnecessary.

Author: uranusjr

src/pip/_internal/locations/__init__.py

@@ -530,4 +530,4 @@ def get_isolated_environment_lib_paths(prefix: str) -> List[str]:
 
 
 def get_isolated_environment_bin_path(prefix: str) -> str:
-    return _sysconfig.get_isolated_environment_bin_path(prefix)
+    return _sysconfig.get_isolated_environment_paths(prefix)["scripts"]

src/pip/_internal/locations/_sysconfig.py

@@ -213,18 +213,13 @@ def get_platlib() -> str:
     return sysconfig.get_paths()["platlib"]
 
 
-def _get_isolated_environment_paths(prefix: str) -> typing.Dict[str, str]:
+def get_isolated_environment_paths(prefix: str) -> typing.Dict[str, str]:
     variables = {"base": prefix, "platbase": prefix}
     if "venv" in sysconfig.get_scheme_names():
         return sysconfig.get_paths(vars=variables, scheme="venv")
     return sysconfig.get_paths(vars=variables)
 
 
 def get_isolated_environment_lib_paths(prefix: str) -> typing.Tuple[str, str]:
-    paths = _get_isolated_environment_paths(prefix)
+    paths = get_isolated_environment_paths(prefix)
     return (paths["purelib"], paths["platlib"])
-
-
-def get_isolated_environment_bin_path(prefix: str) -> str:
-    paths = _get_isolated_environment_paths(prefix)
-    return paths["scripts"]