render cleanup RBAC only for KubernetesExecutor

[henry3260]

Why

cleanup Role and RoleBinding were rendered whenever cleanup.enabled was true, even when cleanup CronJob and cleanup ServiceAccount were not rendered.
This created inconsistent chart output and unnecessary RBAC resources in non-KubernetesExecutor setups.

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[github-actions]

Backport successfully created: chart/v1-2x-test

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

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Status	Branch	Result
✅	chart/v1-2x-test