ci: Lint for viewBox on all SVGs

Purpose

Enforce having a viewBox on svg files. viewBox is beneficial because it helps preserve the aspect ratio of svgs.

Some of the svgs were fixed by !98 (merged) but some files are missing them now, this fixes the new occurrences.

Screenshots

Checklist

For a new icon and/or illustration:

• Link to related design issue:
• If this adds an icon ensure that it follows the new icon checklists.
• If this adds an illustration ensure that it follows the new illustration checklists.

For third-party trademarks:

• If this adds or updates an icon or illustration that includes a third-party trademark, ensure that it follows the process for adding third-party trademarks to GitLab.

Closes #310 (closed)