ci: Drop Python 3.9 support (#1041)

Python 3.9 reached end of life in October 2025.

Author: lord-haffi

.github/workflows/packaging_test.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v5

.github/workflows/python-publish-scheduled.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v5

.github/workflows/tests.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v5

tox.ini

@@ -71,7 +71,6 @@ deps =
     pre-commit
 commands =
     python -m pip install --upgrade pip
-    pip-compile requirements.in
     pip install -r requirements.txt
     pre-commit install