feat(ci): add matcher for setuptools warnigs

This should collect errors seen in WeblateOrg#12778.

.github/matchers/setuptools.json

@@ -0,0 +1,14 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "setuptools",
+      "severity": "warning",
+      "pattern": [
+        {
+          "message": 1,
+          "regexp": "^[^:]*:\\d+: _Warning: (.*)$"
+        }
+      ]
+    }
+  ]
+}

.github/matchers/setuptools.json.license

@@ -0,0 +1,5 @@
+Copyright © Michal Čihař <[email protected]>
+
+SPDX-License-Identifier: CC0-1.0
+
+This file is maintained in https://github.com/WeblateOrg/meta/

.github/workflows/setup.yml

@@ -108,7 +108,10 @@ jobs:
       with:
         python-version: '3.12'
     - name: build
-      run: uv build
+      run: |
+        echo "::add-matcher::.github/matchers/setuptools.json"
+        uv build
+        echo "::remove-matcher owner=setuptools::"
     - name: Sign the dists with Sigstore
       if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags/weblate')
       uses: sigstore/[email protected]