ci: Update GitHub Actions dependencies and Python versions

Updates GitHub Actions checkout (v3->v4) and setup-python (v4->v5).
Upgrades Python from 3.8/3.11 to 3.9/3.13 across all workflows.

Author: knopki

.github/workflows/linter.yml

@@ -12,17 +12,17 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.8"]
+        python-version: ["3.9"]
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         if: ${{ !env.ACT }} # skip during local actions testing
         with:
           fetch-depth: 0
 
       - name: Setup Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
           cache: pip
@@ -51,4 +51,4 @@ jobs:
         run: pylint -E yascheduler
 
       - name: pyupgrade
-        run: pyupgrade --py38-plus --keep-percent-format
+        run: pyupgrade --py39-plus --keep-percent-format

.github/workflows/pr.yml

@@ -16,13 +16,13 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         if: ${{ !env.ACT }} # skip during local actions testing
 
       - name: Setup Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.11
+          python-version: 3.13
           cache: pip
           cache-dependency-path: pyproject.toml
 

.github/workflows/push.yml

@@ -18,15 +18,15 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         if: ${{ !env.ACT }} # skip during local actions testing
         with:
           fetch-depth: 0
 
       - name: Setup Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.11
+          python-version: 3.13
           cache: pip
           cache-dependency-path: pyproject.toml
 

.github/workflows/release.yml

@@ -16,15 +16,15 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         if: ${{ !env.ACT }} # skip during local actions testing
         with:
           fetch-depth: 0
 
       - name: Setup Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.11
+          python-version: 3.13
           cache: pip
           cache-dependency-path: pyproject.toml