feat: add reportOnly flag to checkA11y

[hitshiroya]

Summary

This PR introduces a reportOnly flag to the checkA11y Cypress command. When enabled, it allows users to see accessibility violations without failing the test.

Why?

Some users may want to report accessibility issues in CI but not fail the pipeline. This flag supports that use case. specially for report generation.

Notes

• Backward compatible
• Default behavior remains unchanged
• Example usage:

  it('Check reportOnly flag passes tests', () => {
	cy.visit('https://www.ibm.com/in-en/careers/search');
	cy.injectAxe();
	cy.checkA11y({ reportOnly: true }, { retries: 0, interval: 10 });
});

[hitshiroya]

Hi, @NicholasBoll. Could you review this code changes, please?
Thanks,
Hit