Update CI Node versions to 18/16/14 (#238)

Author: jathak

.github/workflows/ci.yml

@@ -1,10 +1,8 @@
 name: CI
 
 env:
-  # Run on Node 14 because node-fibers doesn't support odd-numbered Node
-  # versions. Note: when changing this, also change
-  # jobs.node_tests.strategy.matrix.node_version.
-  DEFAULT_NODE_VERSION: 14
+  # Note: when changing this, also change jobs.node_tests.strategy.matrix.node_version.
+  DEFAULT_NODE_VERSION: 18
 
 on:
   push:
@@ -50,15 +48,15 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
         dart_channel: [stable]
-        node_version: [14]
+        node_version: [18]
         include:
           # Include LTS versions on Ubuntu
           - os: ubuntu-latest
             dart_channel: stable
-            node_version: 12
+            node_version: 16
           - os: ubuntu-latest
             dart_channel: stable
-            node_version: 10
+            node_version: 14
           - os: ubuntu-latest
             dart_channel: dev