Revert "[1.7.x] Fixed #23892 -- Made deconstructible classes forwards compatible"

This reverts commit 8014001d9287d516c58be80ad71fb63593648b3d.

Adding kwargs to deconstructed objects does not achieve useful
forward-compatibility in general, since the additional kwargs are silently
dropped rather than having their expected effect. In fact, it can cause the
failure to be more difficult to debug. Thanks Shai Berger for discussion.
[1.7.x] Fixed #23900 -- Added missing imports in code example.

The Preventing header injection example included
classes that are not imported.

Thanks to Collin Anderson and Berker Peksağ for the
reviews.

Backport of 0d74209ef66111f29f122d5f5fdf8e2964890cc5 from master.