Drop support for Python 3.9 which reaches end of life soon

Author: mitya57

.github/workflows/main.yml

@@ -6,7 +6,7 @@ jobs:
   test:
     strategy:
       matrix:
-        python: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        python: ['3.10', '3.11', '3.12', '3.13']
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5

pyproject.toml

@@ -13,15 +13,14 @@ classifiers = [
     "Operating System :: POSIX",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3 :: Only",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Topic :: Security",
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = ["cryptography>=2.0", "jeepney>=0.6"]
 
 [project.readme]