[TK-1960] Mark attribute default_secret_name as deprecated in the documentation

[arybolovlev]

Description

Mark attribute default_secret_name as deprecated in the documentation.

Release Note

Release note for CHANGELOG:

`resource/kubernetes_service_account`: mark attribute `default_secret_name` as deprecated
`resource/kubernetes_service_account_v1`: mark attribute `default_secret_name` as deprecated

References

Fix: #1878

Community Note

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[github-actions]

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