Make port not found page dark theme aware

[gtsiolis]

Problem to solve

The product already adapts to dark or system theme for the dashboard (see #6747) and the editor (see #6403).

However, the Port XYZ Not Found page is still using light only theme.

Port XYZ Not Found

Proposal

Let's make Port XYZ Not Found page adapt to system or dark theme aware. 🌔

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[gtsiolis]

Although this is minor, reopening and marking as never stale for now.