chore: add missing SPDX ID and workflow check (#13570)

* chore: add workflow which checks if SPDX ID exists

* chore: add missing SPDX ID in some files

* chore: change trigger condition

* chore: trigger on push

* lint

cypress/e2e/basic.cy.js

@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 describe('Before setup instance', () => {
 	beforeEach(() => {
 		cy.resetState();

cypress/e2e/router.cy.js

@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 describe('Router transition', () => {
 	describe('Redirect', () => {
 		// サーバの初期化。ルートのテストに関しては各describeごとに1度だけ実行で十分だと思う（使いまわした方が早い）

cypress/e2e/widgets.cy.js

@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 /* flaky
 describe('After user signed in', () => {
 	beforeEach(() => {