fix: milestone popover date wrapping

Relates to issue #81104 (moved)

Changes

This MR fixes the milestone popover date wrapping issue by making three key improvements to app/assets/javascripts/issuable/popover/components/milestone_popover.vue:

1. Removed minimum width constraint
   • Removed :css-classes="['gl-min-w-34']" prop from the <gl-popover> component
   • The popover now sizes naturally based on content, consistent with issue and MR popovers
2. Removed title width constraint
   • Changed class="gl-my-3 gl-max-w-30" to class="gl-my-3" on the title heading
   • The title can now use available space naturally without artificial constraints
3. Added flex-wrap to first row layout
   • Changed class="gl-flex gl-items-center gl-gap-2" to class="gl-flex gl-flex-wrap gl-items-center gl-gap-2"
   • The timeframe text will now wrap to a complete new line gracefully when needed, rather than breaking mid-text

The changes made by Duo were incorrect. I have manually edited this MR -- all that was needed was gl-whitespace-nowrap on the milestone dates.

Before	After

Expected Improvements:

✅ No more awkward mid-text wrapping of milestone dates
✅ Popover sizes naturally based on content
✅ Better user experience across different languages
✅ Consistent behavior with other popover components
✅ More flexible and responsive layout