Add deleteLink().

[dereuromark]

Docs for cakephp/cakephp#18144

[ADmad]

/home/runner/work/docs/docs/en/appendices/5-2-migration-guide.rst:87: CRITICAL: Unexpected section title.

View
---- [docutils]
/home/runner/work/docs/docs/en/views/helpers/form.rst:2174: WARNING: Title underline too short.

Creating DELETE Links
------------------- [docutils]
/home/runner/work/docs/docs/en/views/helpers/form.rst:2174: WARNING: Title underline too short.

This seems to be the cause of the build failure.