Remove 'pip' command hint from release announcement

While of course `pip` is still the most used tool to install packages, currently there are a lot of alternatives (`poetry`, `uv`, etc), so it feels a bit dated to suggest `pip install --upgrade` directly on the release announcement.

Also, all the other release notes do not mention `pip` too, so it makes sense to remove it from the patch release announcement.

Author: nicoddemus

scripts/release.patch.rst

@@ -3,9 +3,7 @@ pytest-{version}
 
 pytest {version} has just been released to PyPI.
 
-This is a bug-fix release, being a drop-in replacement. To upgrade::
-
-  pip install --upgrade pytest
+This is a bug-fix release, being a drop-in replacement.
 
 The full changelog is available at https://docs.pytest.org/en/stable/changelog.html.