refactor: Delete Qunit test files

Since it is no longer used

payments/payment_gateways/doctype/braintree_settings/test_braintree_settings.js

@@ -1,23 +0,0 @@
-/* eslint-disable */
-// rename this file from _test_[name] to test_[name] to activate
-// and remove above this line
-
-QUnit.test("test: Braintree Settings", function (assert) {
-	let done = assert.async();
-
-	// number of asserts
-	assert.expect(1);
-
-	frappe.run_serially([
-		// insert a new Braintree Setting
-		() => frappe.tests.make('Braintree Settings', [
-			// values to be set
-			{key: 'value'}
-		]),
-		() => {
-			assert.equal(cur_frm.doc.key, 'value');
-		},
-		() => done()
-	]);
-
-});

payments/payment_gateways/doctype/stripe_settings/test_stripe_settings.js

@@ -1,23 +0,0 @@
-/* eslint-disable */
-// rename this file from _test_[name] to test_[name] to activate
-// and remove above this line
-
-QUnit.test("test: Stripe Settings", function (assert) {
-	let done = assert.async();
-
-	// number of asserts
-	assert.expect(1);
-
-	frappe.run_serially([
-		// insert a new Stripe Settings
-		() => frappe.tests.make('Stripe Settings', [
-			// values to be set
-			{key: 'value'}
-		]),
-		() => {
-			assert.equal(cur_frm.doc.key, 'value');
-		},
-		() => done()
-	]);
-
-});

payments/payments/doctype/payment_gateway/test_payment_gateway.js

@@ -1,23 +0,0 @@
-/* eslint-disable */
-// rename this file from _test_[name] to test_[name] to activate
-// and remove above this line
-
-QUnit.test("test: Payment Gateway", function (assert) {
-	let done = assert.async();
-
-	// number of asserts
-	assert.expect(1);
-
-	frappe.run_serially([
-		// insert a new Payment Gateway
-		() => frappe.tests.make('Payment Gateway', [
-			// values to be set
-			{key: 'value'}
-		]),
-		() => {
-			assert.equal(cur_frm.doc.key, 'value');
-		},
-		() => done()
-	]);
-
-});