Add Prow setup for feature flag tests

This commit adds the prow setup for feature flag tests.

/kind misc
fixes: tektoncd#1629

prow/config.yaml

@@ -2085,3 +2085,57 @@ periodics:
       env:
       - name: TEST_RUN_ALL_TESTS
         value: "true"
+- cron: "6 4 * * *"
+  name: ci-tekton-pipeline-feature-flag-tests
+  labels:
+    preset-presubmit-sh: "true"
+    preset-dind-enabled: "true"
+    preset-kind-volume-mounts: "true"
+  agent: kubernetes
+  decorate: true
+  extra_refs:
+  - org: tektoncd
+    repo: pipeline
+    base_ref: main
+    path_alias: github.com/tektoncd/pipeline
+  spec:
+    nodeSelector:
+      cloud.google.com/gke-ephemeral-storage-local-ssd: "true"
+      cloud.google.com/gke-nodepool: n2-standard-4-kind
+    tolerations:
+      - key: kind-only
+        operator: Equal
+        value: "true"
+        effect: NoSchedule
+    containers:
+    - image: gcr.io/tekton-releases/dogfooding/test-runner@sha256:11dc05cf6e81786ce5935e43aad29a84d6b662804cb57f740c9fb3e1e73ff5f7 # golang 1.19
+      imagePullPolicy: Always
+      command:
+        - /usr/local/bin/entrypoint.sh
+      args:
+      - "--service-account=/etc/test-account/service-account.json"
+      - "--" # end bootstrap args, scenario args below
+      - "--" # end kubernetes_execute_bazel flags (consider following flags as text)
+      - "/usr/local/bin/kind-e2e"
+      - "--k8s-version"
+      - "v1.25.x"
+      - "--nodes"
+      - "3"
+      - "--e2e-script"
+      - "./test/e2e-tests.sh"
+      - "--e2e-env"
+      - "./test/e2e-tests-kind-prow.env"
+      securityContext:
+        privileged: true
+      resources:
+        requests:
+          cpu: 3500m
+          memory: 4Gi
+        limits:
+          cpu: 3500m
+          memory: 8Gi
+      env:
+      - name: RUN_FEATUREFLAG_TESTS
+        value: "true"
+      - name: E2E_GO_TEST_TIMEOUT
+        value: "60m"