Merge branch 'feature-custom-mounts' into 'master'

feat: Allow configuring additional volumes, and volume mounts

See merge request https://gitlab.com/gitlab-org/cluster-integration/auto-deploy-image/-/merge_requests/304



Merged-by: Shinya Maeda <shinya@gitlab.com>
Approved-by: João Alexandre Cunha <j.a.cunha@gmail.com>
Approved-by: Shinya Maeda <shinya@gitlab.com>
Co-authored-by: MBcom <27956078+MBcom@users.noreply.github.com>