add missing env keyword in Env._run (#7626)

The env keyword contains the modified path (that uses get_temp_environ)
so without it, anything using the `input` path here would get the wrong
env.

fixes python-poetry#7623

Author: novas0x2a

src/poetry/utils/env.py

@@ -1533,6 +1533,7 @@ def _run(self, cmd: list[str], **kwargs: Any) -> int | str:
                     stderr=stderr,
                     input=encode(input_),
                     check=True,
+                    env=env,
                     **kwargs,
                 ).stdout
             elif call: