use node 18 to support github electron-builder action

app/package.json

@@ -10,7 +10,7 @@
     "mochatest": "mocha --require ts-node/register src/**/*.spec.ts"
   },
   "engines": {
-    "node": "19"
+    "node": ">=18"
   },
   "author": "",
   "license": "CC-BY-ND-4.0",
@@ -90,4 +90,4 @@
   "peerDependencies": {
     "electron": "^29"
   }
-}
+}

backend/package.json

@@ -12,7 +12,7 @@
     "postinstall": "yarn build"
   },
   "engines": {
-    "node": "19"
+    "node": ">=18"
   },
   "author": "",
   "license": "CC-BY-ND-4.0",

package.json

@@ -4,7 +4,7 @@
   "description": "Explore your message queues",
   "main": "dist/src/electron.js",
   "engines": {
-    "node": "19"
+    "node": ">=18"
   },
   "scripts": {
     "start": "electron .",
@@ -123,4 +123,4 @@
     "uuid": "^8.3.2",
     "yarn-run-all": "^3.1.1"
   }
-}
+}