Remove Python 3.9 support

Python 3.9 has reached it's end-of-life in last october. Let's support supporting it.

Author: moi15moi

.github/workflows/run_test.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
 
     steps:
     - name: Checkout code

pyproject.toml

@@ -7,7 +7,7 @@ authors = [
 license = "MIT"
 license-files = ["LICENSE"]
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "ass>=1.0.0, < 2",
     "ass-tag-analyzer < 1",
@@ -22,7 +22,6 @@ classifiers=[
         "Intended Audience :: End Users/Desktop",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",