fix(deps): require google-gax v2.12.0 (#135)

Author: alexander-fenster

package.json

@@ -29,7 +29,7 @@
     "api-documenter": "api-documenter yaml --input-folder=temp"
   },
   "dependencies": {
-    "google-gax": "^2.9.2",
+    "google-gax": "^2.12.0",
     "json-schema": "^0.3.0"
   },
   "devDependencies": {