Bump GitHub Actions and Python package versions

Updated dependencies to latest stable versions:
- actions/checkout: v4 → v5
- actions/setup-python: v5 → v6
- black: 25.1.0 → 25.9.0
- macOS runner: macos-14 → macos-15

Author: jserv

.github/workflows/package.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
     - name: Set up Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.12'
 
@@ -38,7 +38,7 @@ jobs:
         pip install --user setuptools wheel
 
     - name: Check out Kconfiglib source code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
 
     - name: Build source distribution
       run: |

.github/workflows/style.yml

@@ -13,17 +13,17 @@ jobs:
 
     steps:
     - name: Check out Kconfiglib source code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
 
     - name: Set up Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: '3.12'
 
     - name: Install tools
       run: |
            sudo apt-get install -q=2 shfmt python3-pip
-           pip3 install black==25.1.0
+           pip3 install black==25.9.0
 
     - name: Run format check
       run: |

.github/workflows/test.yml

@@ -36,7 +36,7 @@ jobs:
           builder: ubuntu-24.04
         - python: '3.12'
           os: macOS
-          builder: macos-14
+          builder: macos-15
         # - python: '3.12'
         #   os: Windows
         #   builder: windows-2022
@@ -51,7 +51,7 @@ jobs:
         fi
 
     - name: Set up Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: ${{ matrix.target.python }}
 
@@ -67,15 +67,15 @@ jobs:
         pip install --user setuptools wheel
 
     - name: Check out Linux source code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       # On Windows, checkout of 'aux.c' is expected to fail because ... Windows.
       continue-on-error: true
       with:
         repository: torvalds/linux
         ref: v5.4
 
     - name: Check out Kconfiglib source code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       with:
         path: Kconfiglib