fix: ci runner

Author: bzp2010

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
           - "1.25.3.1"
           - "1.27.1.1"
 
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-latest"
 
     env:
       OPENRESTY_VERSION: ${{ matrix.op_version }}

.github/workflows/lint.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   build:
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-latest"
 
     steps:
       - name: Check out code