Script Loader: Print import map before classic scripts.

Should any scripts contain calls to `import()`, the browser won't be able to resolve bare import specifiers unless the import map is already in the DOM. Thus, rather than rely on hook registration order, which is fallible, ensure that the newer callback `WP_Script_Modules::print_import_map` (since 6.5.0) has a lower priority than `_wp_footer_scripts`.

Reviewed by jonsurrell.
Props mlaetitia.
Fixes #64907.



git-svn-id: https://develop.svn.wordpress.org/trunk@62080 602fd350-edb4-49c9-b593-d223f7449a82