[8.x] [ci/response_ops.yml] Increase parallelism (#207941) (#208107)

# Backport

This will backport the following commits from `main` to `8.x`:
- [[ci/response_ops.yml] Increase parallelism
(#207941)](https://github.com/elastic/kibana/pull/207941)

<!--- Backport version: 9.4.3 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT
[{"author":{"name":"Jon","email":"jon@elastic.co"},"sourceCommit":{"committedDate":"2025-01-23T17:15:48Z","message":"[ci/response_ops.yml]
Increase parallelism (#207941)\n\nThese tests have moved beyond our 40
minute
target.","sha":"0a577beec5b70e5a193071602c5994553d03b420","branchLabelMapping":{"^v9.0.0$":"main","^v8.18.0$":"8.x","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:skip","v9.0.0","ci:all-cypress-suites","backport:prev-minor"],"title":"[ci/response_ops.yml]
Increase
parallelism","number":207941,"url":"https://github.com/elastic/kibana/pull/207941","mergeCommit":{"message":"[ci/response_ops.yml]
Increase parallelism (#207941)\n\nThese tests have moved beyond our 40
minute
target.","sha":"0a577beec5b70e5a193071602c5994553d03b420"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v9.0.0","branchLabelMappingKey":"^v9.0.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/207941","number":207941,"mergeCommit":{"message":"[ci/response_ops.yml]
Increase parallelism (#207941)\n\nThese tests have moved beyond our 40
minute target.","sha":"0a577beec5b70e5a193071602c5994553d03b420"}}]}]
BACKPORT-->

Co-authored-by: Jon <jon@elastic.co>

.buildkite/pipelines/pull_request/response_ops.yml

@@ -13,7 +13,7 @@ steps:
       - check_types
       - check_oas_snapshot
     timeout_in_minutes: 120
-    parallelism: 9
+    parallelism: 11
     retry:
       automatic:
         - exit_status: '*'