add Alpine 3.22 support

Author: aphralG

.github/workflows/ci.yml

@@ -244,12 +244,12 @@ jobs:
           matrix:
               container:                
                   - image: "alpine"
-                    version: "3.21"
+                    version: "3.20"
                     plus: "r32"
                     release: "alpine"
                     path: "/nginx-plus/agent"
                   - image: "alpine"
-                    version: "3.20"
+                    version: "3.19"
                     plus: "r31"
                     release: "alpine"
                     path: "/nginx-plus/agent"