Set queue subnet to the same HeadNode subnet

Description

Reduce cross-AZs costs by selecting the same subnet of the HeadNode for the queues.

Kept the default subnet assigned to the Head node: the same subnet is assigned to the queue and dry run succeeds
Changed the default subnet assigned to the Head node: the same subnet is assigned to the queue and dry run succeeds

[x] I added tests to new or existing code
[ ] I removed hardcoded strings and used react-i18next library (useTranslation hook and/or Trans component), see an example here
[ ] I made sure no sensitive info gets logged at any time in the codebase (see here) (e.g. no user info or details, no stacktraces, etc.)
[ ] I made sure that any GitHub issue solved by this PR is correctly linked
[ ] I checked that infrastructure/update_infrastructure.sh runs without any error
[x] I checked that npm run build builds without any error
[ ] I checked that clusters are listed correctly
[x] I checked that a new cluster can be created (config is produced and dry run passes)
[] I checked that login and logout work as expected

In order to increase the likelihood of your contribution being accepted, please make sure you have read both the Contributing Guidelines and the Project Guidelines

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.