build!: update library to use Node 12 (#604)

* build!: Update library to use Node 12
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: sofisl

packages/google-cloud-texttospeech/package.json

@@ -5,7 +5,7 @@
   "license": "Apache-2.0",
   "author": "Google LLC",
   "engines": {
-    "node": ">=10"
+    "node": ">=12.0.0"
   },
   "repository": "googleapis/nodejs-text-to-speech",
   "main": "build/src/index.js",
@@ -43,25 +43,25 @@
     "precompile": "gts clean"
   },
   "dependencies": {
-    "google-gax": "^2.24.1"
+    "google-gax": "^3.0.1"
   },
   "devDependencies": {
     "@types/mocha": "^9.0.0",
     "@types/node": "^16.0.0",
     "@types/sinon": "^10.0.0",
     "c8": "^7.0.0",
     "codecov": "^3.0.0",
-    "gts": "^3.0.0",
+    "gts": "^3.1.0",
     "jsdoc": "^3.5.5",
     "jsdoc-fresh": "^1.0.1",
     "jsdoc-region-tag": "^1.0.2",
     "linkinator": "^2.0.0",
-    "mocha": "^8.0.0",
+    "mocha": "^9.2.2",
     "null-loader": "^4.0.0",
     "pack-n-play": "^1.0.0-2",
     "sinon": "^14.0.0",
     "ts-loader": "^9.0.0",
-    "typescript": "^3.8.3",
+    "typescript": "^4.6.4",
     "webpack": "^5.0.0",
     "webpack-cli": "^4.0.0"
   }

packages/google-cloud-texttospeech/samples/package.json

@@ -8,7 +8,7 @@
     "*.js"
   ],
   "engines": {
-    "node": ">=8"
+    "node": ">=12.0.0"
   },
   "scripts": {
     "test": "mocha --timeout=60000"