Update to node 18+. Update all deps, except chai and chai-as-promised

Author: MarkDuckworth

.eslintrc.json

@@ -34,7 +34,8 @@
             "object": "it",
             "property": "only"
           }
-        ]
+        ],
+        "@typescript-eslint/no-floating-promises": ["off"]
       }
     }
   ]

.github/.OwlBot.lock.yaml

@@ -1,4 +1,4 @@
-# Copyright 2024 Google LLC
+# Copyright 2025 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,5 +13,4 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-nodejs:latest
-  digest: sha256:0d39e59663287ae929c1d4ccf8ebf7cef9946826c9b86eda7e85d8d752dbb584
-# created: 2024-11-21T22:39:44.342569463Z
+  digest: sha256:ebf1487fdb5be0d02d49a20b01547be3cd15cbd03f4ded7b47c65eae7920a080