Update CI to use node v16 and v18.

Author: lgarron

.github/workflows/build.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [14.x, 16.x]
+        node-version: [16.x, 18.x]
 
     steps:
       - uses: actions/checkout@v2

.github/workflows/pages.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [16.x]
+        node-version: [18.x]
 
     steps:
       - uses: actions/checkout@v2

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [14.x, 16.x]
+        node-version: [16.x, 18.x]
 
     steps:
       - uses: actions/checkout@v2