Revert "feat: added hasError param to OSS::TextArea"

[OwenCoogan]

Reverts #627

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Note

Removes the @hasError API from OSS::TextArea and reverts its styling logic to rely solely on @errorMessage for the container error state.

• text-area.ts: deletes hasError arg/computed; no longer applies oss-textarea--errored to the textarea; keeps resize validation/classes
• text-area.hbs: error container class now driven by @errorMessage; renders message when provided
• Storybook: removes hasError control/usages; updates examples accordingly
• Tests: removes scenarios asserting @hasError and textarea-level errored class; retains resize and core behavior tests

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[linear]

DRA-4481 [pubslishr-admin-web/oss-components] DraftComment block