plugin_lockdown.php

<?php
/**
 * Limit plugin installations to a single authorized account.
 *
 * @param array  $caps    Meta capabailities.
 * @param string $cap     Primitive capability.
 * @param int    $user_id User ID.
 * @param array  $args    Arguments.
 * @return array Filtered meta capabilities.
 */
function lock_down_plugin_controls( $caps, $cap, $user_id, $args ) {

	// Keep plugins for local and staging.
	if ( strpos( get_site_url(), '.dev' ) || strpos( get_site_url(), 'staging' ) ) {
		return $caps;
	}

	// Specific user ID.
	if ( 55 !== $user_id ) {
		if ( 'edit_plugins' == $cap
			|| 'update_plugins' == $cap
			|| 'delete_plugins' == $cap
			|| 'install_plugins' == $cap
		) {
			$caps[] = 'do_not_allow';
		}
	}
	return $caps;
}
add_filter( 'map_meta_cap', 'lock_down_plugin_controls', 10, 4 );