ci: ns7zip build uses --dist; collect dist/

ns7zip now supports --dist (commit 57133b7 on nsis-plugin-ns7zip):
DLLs land in <repo>/dist/<config>. Build with `python build_plugin.py
--dist` and collect artifact-source 'dist'.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitea/workflows/build-ns7zip.yml

@@ -28,11 +28,11 @@ jobs:
       - uses: https://gitea.emulab.it/Simone/local-ci-cd-system/.gitea/actions/local-ci-build@main
         with:
           # build_plugin.py auto-detects host/toolset and builds all
-          # configs by default; --final/--dist-dir do not exist (they were
-          # forwarded to the per-version script and rejected). Output DLLs
-          # are copied to <repo>/plugins/{x86-ansi,x86-unicode,amd64-unicode}.
-          build-command:   'python build_plugin.py'
-          artifact-source: 'plugins'
+          # configs by default; --dist forwards to the per-version script
+          # which copies the DLLs to <repo>/dist/<config> instead of the
+          # committed plugins/ dir.
+          build-command:   'python build_plugin.py --dist'
+          artifact-source: 'dist'
           submodules:      'true'
           guest-os:        ${{ matrix.target == 'linux' && 'Linux' || 'Windows' }}
           # repo-url uses the host SSH alias `gitea-ci` (~/.ssh/config),