feat: Add kube_deployment_spec_topology_spread_constraints metric for issue #2701

[SoumyaRaikwar]

What this PR does / why we need it

This PR adds the kube_deployment_spec_topology_spread_constraints metric that counts the number of topology spread constraints defined in a deployment's pod template specification.

This PR solves the topology spread constraints monitoring requirement from issue #2701, which specifically requested visibility into scheduling primitives including "pod topology spread constraints" for workload pod distribution monitoring.

Which issue(s) this PR fixes

Solves topology spread constraints monitoring from #2701 - Add schedule spec and status for workload

Problem Solved

Issue #2701 identified that operators need to monitor various scheduling primitives to detect when "break variation may happen because pod priority preemption or node pressure eviction."

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This pull-request has been approved by: SoumyaRaikwar
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