general: python3.9 reached EOL, switch min version

also enable 3.13 on CI

.github/workflows/main.yml

@@ -21,19 +21,20 @@ on:
 jobs:
   build:
     strategy:
+      fail-fast: false
       matrix:
         platform: [ubuntu-latest, macos-latest,  windows-latest]
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
         exclude: [
             # windows runners are pretty scarce, so let's only run lowest and highest python version
-            {platform: windows-latest, python-version: '3.9' },
             {platform: windows-latest, python-version: '3.10'},
             {platform: windows-latest, python-version: '3.11'},
+            {platform: windows-latest, python-version: '3.12'},
 
             # same, macos is a bit too slow and ubuntu covers python quirks well
-            {platform: macos-latest  , python-version: '3.9'  },
             {platform: macos-latest  , python-version: '3.10' },
             {platform: macos-latest  , python-version: '3.11' },
+            {platform: macos-latest  , python-version: '3.12' },
         ]
 
     runs-on: ${{ matrix.platform }}
@@ -63,11 +64,13 @@ jobs:
     - if: matrix.platform == 'ubuntu-latest'  # no need to compute coverage for other platforms
       uses: actions/upload-artifact@v4
       with:
+        include-hidden-files: true
         name: .coverage.mypy-misc_${{ matrix.platform }}_${{ matrix.python-version }}
         path: .coverage.mypy-misc/
     - if: matrix.platform == 'ubuntu-latest'  # no need to compute coverage for other platforms
       uses: actions/upload-artifact@v4
       with:
+        include-hidden-files: true
         name: .coverage.mypy-core_${{ matrix.platform }}_${{ matrix.python-version }}
         path: .coverage.mypy-core/
 
@@ -81,7 +84,7 @@ jobs:
 
     - uses: actions/setup-python@v5
       with:
-        python-version: '3.8'
+        python-version: '3.10'
 
     - uses: actions/checkout@v4
       with: