Update execa dependency to eliminate Regular Expression Denial of Service vulnerability

[cmacnamara]

HI there! I am getting a high severity vuln alert from Dependabot based on twilio-run's dependency on the execa package:

Is there any way this could be updated to eliminate this vuln? Thanks so much!

[welcome]

Thank you so much for opening your first issue in this project! We'll try to get back to it as quickly as possible. While you are waiting...here's a random picture of a corgi (powered by dog.ceo)