feat: support eslint v8

Bumps eslint to v8, typescript-eslint to v5 and eslint-plugin-vue to v7.17 (first version to support eslint v8).
This commit also drops support for older versions of eslint.

Author: cexbrayat

package.json

@@ -28,10 +28,10 @@
   },
   "homepage": "https://github.com/vuejs/eslint-config-typescript#readme",
   "devDependencies": {
-    "@typescript-eslint/eslint-plugin": "^4.4.0",
-    "@typescript-eslint/parser": "^4.4.0",
-    "eslint": "^7.10.0",
-    "eslint-plugin-vue": "^7.0.1",
+    "@typescript-eslint/eslint-plugin": "^5.0.0",
+    "@typescript-eslint/parser": "^5.0.0",
+    "eslint": "^8.0.0",
+    "eslint-plugin-vue": "^7.17.0",
     "execa": "^4.0.3",
     "jest": "^26.5.2",
     "typescript": "^4.0.3",
@@ -40,10 +40,10 @@
     "vue-property-decorator": "^9.0.2"
   },
   "peerDependencies": {
-    "@typescript-eslint/eslint-plugin": "^4.4.0",
-    "@typescript-eslint/parser": "^4.4.0",
-    "eslint": "^5.0.0 || ^6.0.0 || ^7.0.0",
-    "eslint-plugin-vue": "^5.2.3 || ^6.0.0 || ^7.0.0"
+    "@typescript-eslint/eslint-plugin": "^5.0.0",
+    "@typescript-eslint/parser": "^5.0.0",
+    "eslint": "^8.0.0",
+    "eslint-plugin-vue": "^7.17.0"
   },
   "dependencies": {
     "vue-eslint-parser": "^7.0.0"