Fix/PRESS11-30 capabilities being checked on every pageload

[BrianHenryIE]

Proposed changes

Currently, capabilities requests are being made even for logged out users loading the homepage. This adds a current_user_can() check on $enable_onboarding so it doesn't run unnecessarily and make requests.

https://jira.newfold.com/browse/PRESS11-30

Type of Change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Video

Checklist

• I have read the CONTRIBUTING doc
• I have viewed my change in a web-browser
• Linting and tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

• I first tried to do this in bootstrap.php but current_user_can()'s wp_get_current_user() function had not yet been loaded. Hence the changes to that file.