Disable paraview rendering tests on CI temporarily

[knelli2]

Proposed changes

Turns out #5773 didn't actually fix this issue, it just introduced a new one. I figure let's just temporarily disable the tests until we can actually figure things out so we can get CI working again.

Upgrade instructions

Code review checklist

• The code is documented and the documentation renders correctly. Run
  make doc to generate the documentation locally into BUILD_DIR/docs/html.
  Then open index.html.
• The code follows the stylistic and code quality guidelines listed in the
  code review guide.
• The PR lists upgrade instructions and is labeled bugfix or
  new feature if appropriate.

Further comments

[nilsvu]

It's strange that the apt-get installation issue didn't appear yesterday when #5773 was merged. Either way, I agree with disabling temporarily.