Update to Node 18.18

Recent version of Next.js specify 18.17.0 as the minimum version,
as indicated when running `npm install`:

> npm WARN EBADENGINE Unsupported engine {
> npm WARN EBADENGINE   package: 'next@14.0.2',
> npm WARN EBADENGINE   required: { node: '>=18.17.0' },
> npm WARN EBADENGINE   current: { node: 'v18.12.1', npm: '8.19.2' }
> npm WARN EBADENGINE }

This upgrade should be relatively safe, since Node is only used in
the build process.

I also pinned npm to the version bundled with this version of Node,
as suggested by Volta after pinning the Node version:

>   note: this version of Node includes npm@9.8.1, which is higher than your pinned version (8.19.2).
>      To use the version included with Node, run `volta pin npm@bundled`

.circleci/config.yml

@@ -29,7 +29,7 @@ executors:
 jobs:
   build_frontend:
     docker:
-      - image: cimg/node:18.12
+      - image: cimg/node:18.18
         auth:
           username: $DOCKER_USER
           password: $DOCKER_PASS
@@ -49,7 +49,7 @@ jobs:
 
   test_frontend:
     docker:
-      - image: cimg/node:18.12
+      - image: cimg/node:18.18
         auth:
           username: $DOCKER_USER
           password: $DOCKER_PASS

frontend/netlify.toml

@@ -18,4 +18,4 @@
   # Default build command.
   command = "npm install; npm run build:mocked"
 
-  environment = { NODE_VERSION = "18.12.1", NPM_VERSION = "8.19.2" }
+  environment = { NODE_VERSION = "18.18.2", NPM_VERSION = "9.8.1" }

frontend/package.json

@@ -71,8 +71,8 @@
     "typescript": "^5.2.2"
   },
   "volta": {
-    "node": "18.12.1",
-    "npm": "8.19.2"
+    "node": "18.18.2",
+    "npm": "9.8.1"
   },
   "overrides": {
     "react@<18": "18.2.0"

package.json

@@ -11,8 +11,8 @@
     "dotenv": "^16.3.1"
   },
   "volta": {
-    "node": "18.12.1",
-    "npm": "8.19.2"
+    "node": "18.18.2",
+    "npm": "9.8.1"
   },
   "license": "MPL-2.0",
   "private": true,