fix: toBeDisabled now also evaluates disabled prop when element is Text

[rarenatoe]

Summary

Resolves #1801 by ensuring Text components with the disabled prop are correctly identified as disabled by computeAriaDisabled.

Previously, computeAriaDisabled didn't check for the disabled prop on Text elements, causing queries like getByRole('text', { disabled: true }) to fail. The change adds a check to return true when isHostText(element) and props.disabled are both true, aligning react-native-testing-library's behavior with expected accessibility states.

Test plan

New unit tests have been added for computeAriaDisabled to verify this change. These tests cover:

1. Text component with disabled={true}: Asserts computeAriaDisabled returns true.

2. Text component without disabled prop or disabled={false}: Asserts computeAriaDisabled returns false.

3. Existing TextInput behavior: Ensures non-editable TextInput components are still correctly identified as disabled.

4. aria-disabled and accessibilityState.disabled props: Verifies these existing checks continue to function.

The new computeAriaDisabled tests should pass, demonstrating correct handling of the disabled prop on Text components.