Prevent updating plugins having a .git folder inside

prevent-updating-plugins-under-git.php

<?php

/**
 * Prevent updating plugins under git.
 *
 * @param mixed $value Value of site transient.
 *
 * @return object
 */
function prevent_updating_plugins_under_git( $value ) {

	if ( ! is_object( $value ) ) {
		return $value;
	}

	$response = $value->response ?? [];

	foreach ( $response as $plugin_file => $plugin_data ) {
		$slug = explode( '/', $plugin_file )[0];

		if ( is_dir( WP_PLUGIN_DIR . '/' . $slug . '/.git' ) ) {
			unset( $response[ $plugin_file ] );

			$value->no_update[ $plugin_file ] = (object) [
				'id'          => $plugin_data->id,
				'slug'        => $slug,
				'plugin'      => $plugin_data->plugin,
				'new_version' => $plugin_data->version,
				'url'         => '',
				'package'     => '',
				'icons'       => [],
				'banners'     => [],
				'banners_rtl' => [],
				'requires'    => '',
			];
		}
	}

	return $value;
}

add_filter( 'site_transient_update_plugins', 'prevent_updating_plugins_under_git', 20 );