[CHORE] Prevent Mainnet forking tests from executing with custom commit message prefix

[drewstone]

Overview

To prevent the exhaustion of INFURA api keys, we should have a commit message prefix that prevents the execution of those tests. Something like this would allow us to develop and eventually make CI green on the entire test suite only after we're closer to the finish line for a PR.

Message prefix: [wip]

git commit -m"[wip] this shouldn't execute the mainnet forking tests"

[dutterbutter]

Rather than making use of a commit message prefix, we should have a condition to avoid running mainnet forking tests while the PR is in a draft state.

We can still run all other CI jobs as is, once the PR is in a 'ready to review' state the mainnet forking tests would run accordingly and this would avoid forcing specific semantics on commit messages. Thoughts? @drewstone