Disable lazy loading term meta get_block_templates.

[spacedmonkey]

Backport from ​https://github.com/WordPress/gutenberg/pull/47999

There is no need to lazy load in get_block_templates

Trac ticket: https://core.trac.wordpress.org/ticket/58230#ticket

[spacedmonkey]

Ping @hellofromtonya

Added Andrei as reviewer. If the original reviewers can be tagged in wordpress-develop, I suggest adding them here, as they know best about the changes. It also helps the review load to be distributed among everyone.

Code-wise the changes are the same from the original PR. There are no test instructions in any place I've checked (here, trac ticket, or the original PR), so I don't know what I should test or what I need to look at. I'll leave space for others to comment here (happy to help if test instructions are provided).

@oandregal As this is a performance improvement, there is no functional change. So that is not to test other than if the code make sense.

[spacedmonkey]

In 55817:

Editor: Disable lazy loading term meta in get_block_templates.

Pass false to the lazy_load_term_meta parameter given to the WP_Query found in get_block_templates. Template post types only ever have one term assigned to them. So priming term meta, does not help performance as lazy loading term meta is only useful if loading multiple terms. As get_block_templates is run multiple times on a block theme request, this saves processing time.

Props spacedmonkey, andraganescu, ntsekouras, oandregal, westonruter.
Fixes #58230.

​https://github.com/WordPress/wordpress-develop/commit/e4e3bb397e4c92907dc7a9878fef57a5a9ccd4cc

[spacedmonkey]

Dev note: ​https://make.wordpress.org/core/2023/07/13/improvements-to-the-metadata-api-in-wordpress-6-3/