Update CI actions

- update Python used for sphinx build, coverage, testing
- update version of actions used.

Author: petercorke

.github/workflows/master.yml

@@ -17,15 +17,16 @@ jobs:
     strategy:
       matrix:
         os: [windows-latest, ubuntu-22.04, macos-latest]
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        # https://devguide.python.org/versions/
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
         exclude:
           - os: windows-latest
             python-version: "3.11"
           - os: windows-latest
             python-version: "3.12"
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5
       with:
@@ -36,7 +37,7 @@ jobs:
         pip install .[dev]
     - name: Test with pytest
       env:
-        MPLBACKEND: TkAgg
+        MPLBACKEND: Agg
       run: |
         pytest -s --ignore=W605 --timeout=50 --timeout_method=thread
 
@@ -46,11 +47,11 @@ jobs:
     needs: unittest
     runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
-    - name: Set up Python 3.8
+    - uses: actions/checkout@v4
+    - name: Set up Python 3.12
       uses: actions/setup-python@v5
       with:
-        python-version: 3.8
+        python-version: 3.12
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
@@ -61,7 +62,7 @@ jobs:
         coverage report
         coverage xml 
     - name: upload coverage to Codecov
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v5
       with:
         file: ./coverage.xml
   sphinx:

.github/workflows/publish.yml

@@ -16,10 +16,10 @@ jobs:
       max-parallel: 2
       matrix:
         os: [ubuntu-22.04]
-        python-version: [3.8]
+        python-version: [3.12]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up Python
       uses: actions/setup-python@v5
       with:

.github/workflows/sphinx.yml

@@ -8,11 +8,11 @@ jobs:
     runs-on: ubuntu-22.04
     if: ${{ github.event_name != 'pull_request' }}
     steps:
-    - uses: actions/checkout@v2
-    - name: Set up Python 3.8
+    - uses: actions/checkout@v4
+    - name: Set up Python 3.12
       uses: actions/setup-python@v5
       with:
-        python-version: 3.8
+        python-version: 3.12
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip