Bump github.com/google/go-cmp in /test/custom-task-ctrls/wait-task-beta

Bumps [github.com/google/go-cmp](https://github.com/google/go-cmp) from 0.5.9 to 0.6.0.
- [Release notes](https://github.com/google/go-cmp/releases)
- [Commits](google/go-cmp@v0.5.9...v0.6.0)

---
updated-dependencies:
- dependency-name: github.com/google/go-cmp
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

test/custom-task-ctrls/wait-task-beta/go.mod

@@ -4,7 +4,7 @@ go 1.15
 
 require (
 	github.com/emicklei/go-restful v2.16.0+incompatible // indirect
-	github.com/google/go-cmp v0.5.9
+	github.com/google/go-cmp v0.6.0
 	github.com/tektoncd/pipeline v0.52.0
 	k8s.io/api v0.27.6
 	k8s.io/apimachinery v0.27.6