Update build-openwrt.yml

Author: zzh-zzh-zzh

.github/workflows/build-openwrt.yml

@@ -27,7 +27,7 @@ env:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
     - name: Checkout