Vote-3056: usa-alert style update

[clmedders]

Jira ticket

Vote-3056

Description

This PR will address a style regression after the most recent USWDS update. Also a code clean up to combine style sheets that were doing the same thing but also removed no longer needed spacing style due to the update for this component.

Before:

After:

Deployment and testing

Post-deploy steps

1. run lando retune and cd into the votegov theme and run npm run build

QA/Testing instructions

1. Visit the site and ensure the site wide alert no longer has the style regression as found on the live site
2. Also create another site wide alert for emergency to verify no new style regressions
3. Fill out NVRF and verify that alerts in the form are still looking as expected

Checklist for the Developer

• A link to the JIRA ticket has been included above.
• No merge conflicts exist with the target branch.
• Automated tests have passed on this PR.
• A reviewer has been designated.
• Deployment and testing steps have been documented above, if applicable.

Checklist for the Peer Reviewers

• The file changes are relevant to the task objective.
• Code is readable and includes appropriate commenting.
• Code standards and best practices are followed.
• QA/Test steps were successfully completed, if applicable.
• Applicable logs are free of errors.