fix: prevent crash on jsdom when preloading CSSOM

[AriPerkkio]

• cssom package does not implement StyleSheet.media

<< Describe the changes >>

Adds a simple if to check whether StyleSheet has media.

Closes #3753

[CLAassistant]

All committers have signed the CLA.

[stephenmathieson]

The fix LGTM. I don't understand what's going on with CI though.

[straker]

Thanks for the pr. Could you try pushing an empty commit to see if that fixes the checks?

git commit -m "trigger build" --allow-empty

[AriPerkkio]

I used the commit --amend to get new commit for re-triggering the build instead of --allow-empty - now the PR approval resetted. 🙃

@stephenmathieson could you re-approve so we'll see if CI is now stable?

[AriPerkkio]

The CI seems to remain stuck. Any ideas what's going on?
As resetting the commits did not fix the CI, should I just create a new PR?

[straker]

Unfortunately I don't know what's going on with Circle. I've looked around but it seems the only answer is to contact Circle support and see if they can fix it. Before I do that though, I'm going to try committing to your pr and see if that triggers the build.

[straker]

Well that seems to have worked.

[straker]

Reviewed for security