[MNT] Replace validate_data with check_array in predict methods

[TheGreatPratyush]

Reference Issues/PRs

N/A

What does this implement/fix? Explain your changes.

This PR replaces validate_data with check_array in the predict, predict_proba, and regressor predict methods.

This makes the input validation in prediction steps more consistent with how sklearn typically handles it.

What should a reviewer concentrate their feedback on?

• Whether using check_array instead of validate_data in prediction methods is appropriate
• Any potential impact on existing prediction behavior

Did you add any tests for the change?

No additional tests were added. The changes were verified by running the classifier and ensuring predictions work as expected.

Any other comments?

This is a small cleanup to make the prediction methods follow sklearn conventions more closely.

PR checklist

• The PR title starts with [MNT]
• Added/modified tests
• Used pre-commit hooks