Show error message on trying to delete last dashboard

[johannaengland]

This is not an actual bug, but something I noticed when working on #3150.

The "Delete dashboard" button is already not shown when there is only one dashboard, so it is not possible for a user to try to delete their last dashboard.

So to reproduce this you need to change this line to actually show that button: https://github.com/Uninett/nav/blob/27b12b527aac40a9702cc515981346e21eab89bf/python/nav/web/templates/webfront/index.html#L147

After that when trying to delete the last dashboard an alert box will be added with the content [Object object] instead of showing the correct error message Cannot delete last dashboard.

Before:

After:

[github-actions[bot]]

🦙 MegaLinter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ PYTHON	black	992		0	13.17s
✅ PYTHON	ruff	988		0	0.1s

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[github-actions[bot]]

Test results

    9 files      9 suites   8m 28s ⏱️ 2 142 tests 2 142 ✅ 0 💤 0 ❌ 4 023 runs  4 023 ✅ 0 💤 0 ❌

Results for commit 7720f56f.

:recycle: This comment has been updated with latest results.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 60.40%. Comparing base (3c80b8b) to head (7720f56). Report is 2 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #3232 +/- ## ======================================= Coverage 60.39% 60.40% ======================================= Files 605 605 Lines 43683 43683 Branches 48 48 ======================================= + Hits 26382 26385 +3 + Misses 17289 17286 -3 Partials 12 12 ```

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[stveit]

Could this be some javascript shenanigans?

[stveit]

Yeah nevermind, just my js scripts werent updated. Had to down-up the containers and now it works fine

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud