fix(Calendar): set the "year button" type to "button" so we don't submit parent forms

[Bloodyaugust]

Motivation

Choosing a year from the year dropdown in the Calendar component submits a parent form, and we don't want that.

Acceptance Criteria

• Button for year selection is not default type "submit"
• Button for year selection is type "button"

PR upkeep checklist

• [x] Change log entry
• [x] Label(s)
• [x] Assignee(s)
• [x] Deployment URL: https://mavenlink.github.io/design-system/webinf-mds-datepicker-year-dropdown-179583869
• [x] (When ready for review) Reviewer(s)
• [x] Green Bigmaven CI check
• [x] DevQA on Bigmaven staging (e.g. does the work need to be imported in the internal design system?)