Themes: Add a new taxonomy template.

This uses the same cascade as tags and categories so the check will first be for the slug first, then the term ID,

In classic themes, you can now use term IDs when creating taxonomy templates. With `taxonomy-$taxonomy-{$term->term_id}.php` templates you don't need to worry about templates breaking if you rename the `Oakland Athletics` term to `Athletics` the way you do if you use slug based template names.

Props swissspidy, sebastian.pisula, jorbin, theMikeD.
Fixes #35326.



git-svn-id: https://develop.svn.wordpress.org/trunk@60994 602fd350-edb4-49c9-b593-d223f7449a82

Author: aaronjorbin

src/wp-includes/template.php

@@ -323,21 +323,24 @@ function get_tag_template() {
  * The hierarchy for this template looks like:
  *
  * 1. taxonomy-{taxonomy_slug}-{term_slug}.php
- * 2. taxonomy-{taxonomy_slug}.php
- * 3. taxonomy.php
+ * 2. taxonomy-{taxonomy_slug}-{term_id}.php
+ * 3. taxonomy-{taxonomy_slug}.php
+ * 4. taxonomy.php
  *
  * An example of this is:
  *
  * 1. taxonomy-location-texas.php
- * 2. taxonomy-location.php
- * 3. taxonomy.php
+ * 2. taxonomy-location-67.php
+ * 3. taxonomy-location.php
+ * 4. taxonomy.php
  *
  * The template hierarchy and template path are filterable via the {@see '$type_template_hierarchy'}
  * and {@see '$type_template'} dynamic hooks, where `$type` is 'taxonomy'.
  *
  * @since 2.5.0
  * @since 4.7.0 The decoded form of `taxonomy-{taxonomy_slug}-{term_slug}.php` was added to the top of the
  *              template hierarchy when the term slug contains multibyte characters.
+ * @since 6.9.0 Added `taxonomy-{taxonomy_slug}-{term_id}.php` to the hierarchy.
  *
  * @see get_query_template()
  *
@@ -357,6 +360,7 @@ function get_taxonomy_template() {
 		}
 
 		$templates[] = "taxonomy-$taxonomy-{$term->slug}.php";
+		$templates[] = "taxonomy-$taxonomy-{$term->term_id}.php";
 		$templates[] = "taxonomy-$taxonomy.php";
 	}
 	$templates[] = 'taxonomy.php';