Add a new block pattern category called Footers

[poena]

New footer block patterns have been added to Gutenberg version 14.0, and the goal is to include these patterns in WordPress 6.1.

To make it easier for users to find these patterns, a new block pattern category should be added.

The patterns have already been built to include the new category, with the slug "footer".
​43157
To match the existing Headers category, I believe the visual label text should be "Footers" (plural).

This should be added to _register_core_block_patterns_and_categories()
in wp-includes\block-patterns.php

Register a new block pattern category with the slug "footer" and the label "Footers", to make it easier to find site footer block patterns.

Trac ticket: #56416

[mcsf]

Thanks for the quick patch! This works well for me and makes sense.

cc @bernhard-reiter as editor tech co-lead for 6.1

[mukesh27]

The PR looks good to me, approved and ready for the merge.

[mcsf]

In 53943:

Block Patterns: Add new Footers category

Quoting poena from the ticket: "[...] To make it easier for users to find these
patterns, a new block pattern category should be added. The patterns have
already been built to include the new category, with the slug "footer" [to]
match the existing Headers category"

Props poena.

Fixes #56416.

[peterwilsoncc]

@mukesh27 added to pros via make/core per review comment above.