chore: add oidc idp for acceptance tests

acceptance/idp/oidc/docker-compose.yaml

@@ -0,0 +1,20 @@
+services:
+  oidcop:
+    image: golang:1.24-alpine
+    container_name: oidcop
+    command: go run main.go
+    environment:
+      API_URL: 'http://localhost:8080'
+      API_DOMAIN: 'localhost:8080'
+      PAT_FILE: '/pat/zitadel-admin-sa.pat'
+      SCHEMA: 'http'
+      HOST: 'localhost'
+      PORT: "8004"
+    working_dir: /oidc
+    ports:
+      - 8004:8004
+    volumes:
+      - "../../pat:/pat"
+      - "./:/oidc"
+    extra_hosts:
+      - "localhost:host-gateway"