fix(build): update Go version requirement to 1.23

go.mod required go >= 1.25.4 but golang:1.25-alpine doesn't exist yet.
Downgrade to go 1.23 which is available in Alpine images and sufficient
for the codebase. Update both deployment and job images to golang:1.23-alpine.

go.mod

@@ -1,6 +1,6 @@
 module github.com/rockliang/poimen/workflows
 
-go 1.25.4
+go 1.23
 
 require (
 	github.com/stretchr/testify v1.12.1

k8s/orchestrator-job.yaml

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

k8s/worker-deployment.yaml

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