Fix overflowing deployments table on the release page

What does this MR do and why?

On the release page, the Deployments table has 7 columns and overflowed its container, clipping the last column (Finished) with no way to reach it. This constrains the release content column (gl-min-w-0) and lets the table scroll horizontally (gl-overflow-x-auto) instead of clipping, and lowers the table's stacking breakpoint to md so it collapses to a card layout earlier on narrower screens.

Screenshots or screen recordings

Before	After

How to set up and validate locally

The Deployments block on a release page only appears when the release's tag has deployments to environments. To create that state and see the overflow:

1. Add a .gitlab-ci.yml that deploys tags to several environments (more rows makes the overflow obvious):

   stages: [deploy]
   
   .deploy:
     stage: deploy
     script: echo "Deploying $CI_COMMIT_TAG"
     rules:
       - if: $CI_COMMIT_TAG
   
   deploy_production:
     extends: .deploy
     environment: production
   
   deploy_staging:
     extends: .deploy
     environment: staging
   
   deploy_canary:
     extends: .deploy
     environment: canary

2. Create a release: Deploy → Releases → New release, enter a new tag name (e.g. v1.0.0) and create it. Creating the tag runs the pipeline, and the deploy jobs record deployments to production / staging / canary for that tag.
3. Open the release: Deploy → Releases → the release you created.
4. Expand Deployments and narrow the browser window. Confirm the table scrolls horizontally to reach the Finished column (previously the last column was clipped with no way to see it), and collapses to a stacked card layout below the md breakpoint.

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