[GH actions] Bump up NodeJS versions

We use the `CustomEvent` class, which [became stable in `v20.13`](https://nodejs.org/api/events.html#class-customevent).

Author: DmitrySharabin

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x, 20.x, 22.x]
+        node-version: [20.x, 22.x, 24.x]
 
     steps:
       - uses: actions/checkout@v3
@@ -31,7 +31,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x, 20.x, 22.x]
+        node-version: [20.x, 22.x, 24.x]
 
     steps:
       - uses: actions/checkout@v3
@@ -47,10 +47,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
-      - name: Use Node.js 18.x
+      - name: Use Node.js 20.x
         uses: actions/setup-node@v3
         with:
-          node-version: 18.x
+          node-version: 20.x
       - run: npm ci
       - run: npm run lint:ci
 
@@ -59,9 +59,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
-      - name: Use Node.js 18.x
+      - name: Use Node.js 20.x
         uses: actions/setup-node@v3
         with:
-          node-version: 18.x
+          node-version: 20.x
       - run: npm ci
       - run: npm run regex-coverage