Update Test Automation Engineer description

I'd like to update the language in the Test Automation Engineer description page to match the job description in Greenhouse.

This removes a line of text that strong Ruby experience is a strict requirement. I don't think it is: someone with some or no Ruby who ticks all of our other boxes could succeed at this role, and a candidate's ability to work within our framework is explicitly tested as part of the interview process so we will be able to check this before hiring someone.

For context, I've had a handful of people I reached out to yesterday indicate they were nervous about applying (or wouldn't apply at all) because of this line. These are folks I picked out personally during linkedin searches who are pretty amazing candidates.