Revert "Delete .venv directory"

This reverts commit 5a2693bd9f.

.venv/lib/python3.9/site-packages/pip/_internal/main.py

@@ -0,0 +1,13 @@
+from typing import List, Optional
+
+
+def main(args=None):
+    # type: (Optional[List[str]]) -> int
+    """This is preserved for old console scripts that may still be referencing
+    it.
+
+    For additional details, see https://github.com/pypa/pip/issues/7498.
+    """
+    from pip._internal.utils.entrypoints import _wrapper
+
+    return _wrapper(args)