Switch linter from semistandard to biome

Uses the recommended rules apart from complexity/useArrowFunction,
which would affect about 1700 lines of code with little benefit
right now. This is something that can be addressed over time.

lib/index.js

@@ -1,8 +1,6 @@
 // Copyright 2013 Lovell Fuller and others.
 // SPDX-License-Identifier: Apache-2.0
 
-'use strict';
-
 const Sharp = require('./constructor');
 require('./input')(Sharp);
 require('./resize')(Sharp);