ci: stop testing against NodeJS v18 (#677)

* build(package): set minimal node version in engines field to v20
BREAKING CHANGE: Drop support for NodeJS v18

* build: set minimal node version in build script to v20

* ci: stop testing against NodeJS v18

Author: wolfy1339

.github/workflows/test.yml

@@ -13,9 +13,9 @@ jobs:
     strategy:
       matrix:
         node_version:
-          - 18
           - 20
           - 22
+          - 24
     steps:
       - uses: actions/checkout@v4
       - name: Use Node.js ${{ matrix.node_version }}

package.json

@@ -81,6 +81,6 @@
     ]
   },
   "engines": {
-    "node": ">= 18"
+    "node": ">= 20"
   }
 }