fix(build): require go 1.22 instead of non-existent go 1.25.4

golang:1.23-alpine doesn't exist yet. Revert to golang:1.22-alpine
and update go.mod to require go 1.22, which matches the available image.

go.mod

@@ -1,6 +1,6 @@
 module github.com/rockliang/poimen/workflows
 
-go 1.23
+go 1.22
 
 require (
 	github.com/stretchr/testify v1.12.1

k8s/orchestrator-job.yaml

@@ -13,7 +13,7 @@ spec:
       restartPolicy: Never
       containers:
       - name: orchestrator
-        image: golang:1.23-alpine
+        image: golang:1.22-alpine
         workingDir: /app
         command: ["/bin/sh", "-c"]
         args:

k8s/worker-deployment.yaml

@@ -15,7 +15,7 @@ spec:
     spec:
       containers:
       - name: worker
-        image: golang:1.23-alpine
+        image: golang:1.22-alpine
         workingDir: /app
         command: ["/bin/sh", "-c"]
         args: