Simplify CI.

.github/workflows/build.yml

@@ -38,13 +38,13 @@ jobs:
         pip list
     - name: Test
       run: |
-        pyver="$(python -c 'import sys; print("{0.major}.{0.minor}".format(sys.version_info))')" &&
-        COVERAGE_FILE=".coverage.$pyver" python -mpytest --cov --cov-branch --cov-report=xml
+        python -mpytest --cov --cov-branch
     - name: Upload coverage
       uses: actions/upload-artifact@v4
       with:
         name: coverage-${{ matrix.python-version }}-${{ matrix.flag }}
-        path: .coverage.*
+        include-hidden-files: true
+        path: .coverage
 
   coverage:
     runs-on: ubuntu-latest
@@ -54,16 +54,13 @@ jobs:
     - uses: actions/setup-python@v5
       with:
         python-version: "3.12"
-    - name: Download
-      uses: actions/download-artifact@v4
-      with:
-        pattern: coverage-*
-        merge-multiple: true
     - name: Run
       run: |
         shopt -s globstar &&
+        GH_TOKEN=${{ secrets.GITHUB_TOKEN }} \
+          gh run download ${{ github.run-id }} -p 'coverage-*' &&
         python -mpip install --upgrade coverage &&
-        python -mcoverage combine .coverage.* &&  # Unifies paths across envs.
+        python -mcoverage combine coverage-*/.coverage &&  # Unifies paths across envs.
         python -mcoverage annotate &&
-        ( grep -HnTC2 '^!' **/*,cover || true ) &&
+        grep -HnTC2 '^!' **/*,cover | sed s/,cover//: &&
         python -mcoverage report --show-missing