Sync mode cleanup

[AtofStryker]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• It's submitted to the dev branch.
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)
• All tests are passing: https://github.com/vuejs/vue-test-utils/blob/dev/.github/CONTRIBUTING.md#development-setup
• New/updated tests are included

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)

Other information:

[lmiller1990]

This is still "draft". do you intend to add something else?

The changes seem pretty standard... no problem here.

[AtofStryker]

@lmiller1990 I actually forgot about this 😆 . I will likely do another audit of this but I think these changes were the bulk of it. Is there anything in particular we should be looking at when cleaning up sync mode?

[lmiller1990]

@AtofStryker no idea - I think most of the sync mode stuff is gone now, I haven't thought about it in a long time.

We could just merge this up now and then I could do a release with your new config handle feature and whatever else has bee merged in lately. what do you think?

[AtofStryker]

@lmiller1990 Sounds like a solid plan to me! If I find anything missed while cleaning up, opening another PR is always an option 🙂