Add npm run build for webapp to test suite

[cpswan]

Is your feature request related to a problem? Please describe.

#1681 fails to build, but there's nothing in the tests to show that:

vite v6.0.11 building for production...
✓ 10 modules transformed.
x Build failed in 212ms
error during build:
[vite-plugin-svelte] [plugin vite-plugin-svelte] src/lib/PolicyUserGroups.svelte (521:52): src/lib/PolicyUserGroups.svelte:521:52 `<tr>` cannot be a child of `<table>`. `<table>` only allows these children: `<caption>`, `<colgroup>`, `<tbody>`, `<thead>`, `<tfoot>`, `<style>`, `<script>`, `<template>`. The browser will 'repair' the HTML (by moving, removing, or inserting elements) which breaks Svelte's assumptions about the structure of your components.
https://svelte.dev/e/node_invalid_placement
file: /home/chris/git/github.com/atsign-foundation/noports/apps/admin/webapp/src/lib/PolicyUserGroups.svelte:521:52

 519 |                                                      {/each}
 520 |                                                      </tbody>
 521 |                                                      <tr>
                                                                ^
 522 |                                                          <td>
 523 |                                                              <button type="button" class="btn btn-sm btn-outline-success" style="font-size:10px"

Describe the solution you'd like

Run npm run build on Dependabot PRs that modify webapp dependencies so that we can get an indication of whether they work or break.