Security: Update to diff 2

Problem/Motivation

diff is currently pinned to 1.10

diff 1.10 has a security advisory SA-CONTRIB-2026-096

diff 2.1.1 should be the new minimum.

There's also vastly improved functionality in the latest diff module (supports all revisionable entity types such as content blocks).

Steps to reproduce

composer audit

Proposed resolution

modify drupalwxt composer.json diff version , pin to ^2.1

drop all diff patches, not needed with diff 2.1.1

Remaining tasks

Make it so

User interface changes

Support for all revisionable entity types

API changes

Some internally yes, but should not affect other modules.

Data model changes

N/A