fs-integration: Remove already grouped duplicate variants

With [1] all possible share configurations are grouped after their
respective backend file system. So those duplicate entries can be
removed reducing the number of jobs in the matrix.

[1] samba-in-kubernetes/sit-environment#117

jobs/fs-integration.yml

@@ -7,10 +7,8 @@
  - 'glusterfs'
  - 'xfs'
  - 'cephfs'
- - 'cephfs.vfs'
  - 'cephfs.mgr.vfs'
  - 'gpfs'
- - 'gpfs.vfs'
  - 'gpfs.scale'
  jobs:
  - 'samba_{file_system}-integration-{git_repo}'