namedPlaceholders cannot be disabled at query level

[wellwelwel]

• As reported in chore: improve coverage and good practices for tests #2472

When setting namedPlaceholders globally (connection level) to true, it's not possible to disable it at the query level.

---

To reproduce, just uncomment this test:

node-mysql2/test/esm/integration/named-placeholders.test.mjs

Lines 18 to 29 in 41d21eb

	// test(() => {
	// const c = createConnection({ namedPlaceholders: true });
	// c.query({ sql: query, namedPlaceholders: false }, values, (err) => {
	// c.end();
	// assert(
	// err || err?.sqlMessage.match(/right syntax to use near ':named'/),
	// 'Enabled in connection config, disabled in query command',
	// );
	// });
	// });

---

The opposite will work fine:

node-mysql2/test/esm/integration/named-placeholders.test.mjs

Lines 31 to 44 in 41d21eb

	test(() => {
	const c = createConnection({ namedPlaceholders: false });
	c.query({ sql: query, namedPlaceholders: true }, values, (err, rows) => {
	c.end();
	assert.ifError(err);
	assert.equal(
	rows[0].result,
	1,
	'Disabled in connection config, enabled in query command',
	);
	});
	});