chore(ci): filter mypy for changed files only

There are too many errors for now so filter pull request output to changed files only.

.github/matchers/mypy.json

@@ -0,0 +1,18 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "mypy",
+      "pattern": [
+        {
+          "regexp": "^([^:]*):(\\d+):(?:(\\d+):)? ([^:]*): (.*?)(?:  \\[(\\S+)\\])?$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "severity": 4,
+          "message": 5,
+          "code": 6
+        }
+      ]
+    }
+  ]
+}

.github/matchers/mypy.json.license

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

.github/workflows/mypy.yml

@@ -21,6 +21,26 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+      with:
+        fetch-depth: 2
+    - name: Get changed files
+      if: github.event_name == 'pull_request'
+      id: changed-files
+      uses: tj-actions/changed-files@v45
+    - name: List all changed files
+      if: github.event_name == 'pull_request'
+      env:
+        ALL_CHANGED_FILES: ${{ steps.changed-files.outputs.all_changed_files }}
+      run: |
+        for file in ${ALL_CHANGED_FILES}; do
+          echo "$file" >> .changed-files
+        done
+        if [ ! -f .changed-files ] ; then
+          echo "No changed files!"
+        else
+          cat .changed-files
+        fi
+
     - name: Install apt dependencies
       run: sudo ./ci/apt-install
     - uses: astral-sh/setup-uv@v3
@@ -36,9 +56,16 @@ jobs:
       run: ./ci/pip-install mypy
 
     - name: Run mypy
-      uses: liskin/gh-problem-matcher-wrap@v3
-      with:
-        linters: mypy
-        run: mypy --show-column-numbers weblate
+      run: mypy --show-column-numbers weblate > mypy.log
       # Temporary hack until we have this fully working
       continue-on-error: true
+    - name: Report mypy
+      if: always()
+      run: |
+        echo "::add-matcher::.github/matchers/mypy.json"
+        if [ -f .changed-files ] ; then
+          grep -F -f .changed-files mypy.log
+        else
+          cat mypy.log
+        fi
+        echo "::remove-matcher owner=mypy::"