Remove test dependencies from root go.mod

Removes test-only dependencies from the production operator module
now that they are isolated in test/extended/tests-extension/go.mod.

Removed dependencies:
- github.com/onsi/ginkgo/v2 v2.23.4
- github.com/onsi/gomega v1.38.0
- github.com/openshift-eng/openshift-tests-extension v0.0.0-20250804142706-7b3ab438a292

Removed replace directive:
- github.com/onsi/ginkgo/v2 => github.com/openshift/onsi-ginkgo/v2

This achieves complete dependency isolation:
- Production go.mod is now free of test framework dependencies
- Test dependencies are managed separately in test/extended/tests-extension/go.mod
- No risk of version conflicts between operator and test framework
- Cleaner dependency tree for production builds

The operator binary no longer carries any testing framework overhead.

Author: gangwgr

go.mod

@@ -16,11 +16,8 @@ require (
 	github.com/google/gofuzz v1.2.0
 	github.com/hashicorp/golang-lru v0.5.4
 	github.com/jteeuwen/go-bindata v3.0.8-0.20151023091102-a0ff2567cfb7+incompatible
-	github.com/onsi/ginkgo/v2 v2.23.4
-	github.com/onsi/gomega v1.38.0
 	github.com/opencontainers/go-digest v1.0.0
 	github.com/opencontainers/image-spec v1.1.1
-	github.com/openshift-eng/openshift-tests-extension v0.0.0-20250804142706-7b3ab438a292
 	github.com/openshift/api v0.0.0-20250820105013-6282350d0c39
 	github.com/openshift/apiserver-library-go v0.0.0-20250710132015-f0d44ef6e53b
 	github.com/openshift/build-machinery-go v0.0.0-20250806130835-622c0378eb0d
@@ -195,7 +192,6 @@ require (
 replace (
 	github.com/distribution/distribution/v3 => github.com/openshift/docker-distribution/v3 v3.0.0-20240215131201-6b2f5d2f1f43
 	github.com/docker/docker => github.com/openshift/moby-moby v0.0.0-20190308215630-da810a85109d
-	github.com/onsi/ginkgo/v2 => github.com/openshift/onsi-ginkgo/v2 v2.6.1-0.20241205171354-8006f302fd12 // This replace is required for we use the OCP fork of Ginkgo
 	k8s.io/api => k8s.io/api v0.33.3
 	k8s.io/apiextensions-apiserver => k8s.io/apiextensions-apiserver v0.33.3
 	k8s.io/apimachinery => k8s.io/apimachinery v0.33.3