Enable more CI integration test clusters (#6180) (#6182)

(cherry picked from commit 7fe1b82)

Author: stevejgordon

.github/workflows/integration-jobs.yml

@@ -46,7 +46,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-elastic-managed-
             
-      - run: "./build.sh integrate ${{ matrix.stack_version }} readonly,writable random:test_only_one --report"
+      - run: "./build.sh integrate ${{ matrix.stack_version }} random:test_only_one --report"
         name: ${{ matrix.stack_version }}
       - name: Results ${{ matrix.stack_version }}
         # only report on if the previous run failed, otherwise this ends up being too noisy