Toggle parcel compilation

[Sinkinson]

A similar request has been raised previously here with no response.

When running the build locally, we can expect the compile gatsby files step to run in less than a second. This same step in our CI takes over 500 seconds. When parcel is run here our CPU usage increases dramatically and causes throttling.

With not using typescript for the gatsby files parcel is targeting —gatsby-config and gatsby-node — we’d ideally like to be able to prevent parcel from running so our build times don’t suffer.

From looking at your tests here, the js files aren’t touched anyway. This is confirmed by the fact that I don’t end up with the targeted files compiled in the .cache/compiled folder.

Is there something I'm missing here, what could be causing parcel to cause such issues in our CI? If parcel could be toggled off, are there any unintended side effects I'm not aware of?

If this is deemed as acceptable I'd be happy to make the PR.