Fixed publish btn dropdown display [ref #7183]

[mheppler]

What this PR does / why we need it:

Extra dropdown-toggle style class snuck into the single-click version of the Publish btn, which triggered the display of the dropdown menu under the button when clicked.

Which issue(s) this PR closes:

Closes #7183 Extraneous Publish Option on Release Candidate

Special notes for your reviewer:

See screenshot in original issue for how the single-click version of the Publish btn should NOT look.

Suggestions on how to test this:

When you click the Publish btn on a dataset with no Submit For Review set up, you should NOT see the dropdown menu displayed, as the screenshot in the original issue shows. If you see a dropdown carrot icon in the button for a dataset WITH the Submit For Review workflow set up, then you should see the dropdown menu, showing the Publish or Return To Author options.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

It fixes a UI bug, returning the page to intended functionality, this is not a change in design.

Is there a release notes update needed for this change?:

No.

Additional documentation:

N/A

[coveralls]

Coverage remained the same at 19.562% when pulling e808e14 on 7183-extraneous-publish-option into 2d632ae on develop.