TAS: support for ElasticWorkloads

[mimowo]

What would you like to be added:

Currently we support TAS and support ElasticWorkloads, but not combined:

This is not supported for two reasons:

1. the workload annotation will get outdated: Allow Pods to identify the workload which admitted them without the "kueue.x-k8s.io/workload" annotation #6480
2. the TopologyAssignment is not copied and adjusted between Workload Slices

An alternative approach which eliminates the need for (1.) is WorkloadResize, but this is also involving: #5897

Why is this needed:

We have users of TAS, and have users for ElasticJobs, unfortunately they cannot yet benefit from both features at the same time.

[mimowo]

cc @mwysokin @ichekrygin @hiboyang

[sohankunkerkar]

/assign @sohankunkerkar

[mimowo]

/priority important-soon