Notice how the parent theme checks if they are already defined e.g.
if ( ! function_exists( 'twenty_twenty_one_entry_meta_footer' ) ) {
...
}
Then just define them in your child theme’s functions.php
file, to override the corresponding template tag.
It should work because the child theme’s functions.php
file is loaded before the parent’s functions.php
file that loads:
// Custom template tags for the theme.
require get_template_directory() . '/inc/template-tags.php';