chore: add disable-dev-shm-usage flag for cypress ci

@jdbrown reported issues with intermittent cypress failures.

One workaround is to mount /dev/shm into the containers, but these issues suggest other workarounds that do not require changes to gitlab runners:

• https://github.com/cypress-io/cypress/issues/5336
• https://gitter.im/cypress-io/cypress/archives/2018/10/17?at=5bc7428c384492366153cf75