chore: release 4.2.0 (#687)

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Author: release-please[bot]

speech/package.json

@@ -15,7 +15,7 @@
     "test": "c8 mocha system-test --timeout 600000"
   },
   "dependencies": {
-    "@google-cloud/speech": "^4.1.5",
+    "@google-cloud/speech": "^4.2.0",
     "@google-cloud/storage": "^5.0.0",
     "chalk": "^4.0.0",
     "node-record-lpcm16": "^1.0.1",