fix: remove Node.js 18.x from CI matrix (requires >=20.9.0 for Next.js)

Author: al7566

.github/workflows/webpack.yml

@@ -12,7 +12,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x, 20.x, 22.x]
+        node-version: [20.x, 22.x]
 
     steps:
     - uses: actions/checkout@v4
@@ -29,4 +29,4 @@ jobs:
       run: bun install
 
     - name: Build
-      run: bun run build
+      run: bun run build