feat: Drop python 3.9 support

Author: keelerm84

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        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:
       - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6

CONTRIBUTING.md

@@ -4,11 +4,11 @@
 
 ### System Requirements
 
-Python 3.9 and above are required.
+Python 3.10 and above are required.
 
 ### Target version(s)
 
-Python 3.9 and above are supported by the SDK.
+Python 3.10 and above are supported by the SDK.
 
 ### Installation and Dependencies
 

README.md

@@ -34,7 +34,7 @@
   </a>
 
   <a href="https://www.python.org/downloads/">
-    <img alt="Min python version" src="https://img.shields.io/badge/python->=3.9-blue.svg" />
+    <img alt="Min python version" src="https://img.shields.io/badge/python->=3.10-blue.svg" />
   </a>
 
   <a href="https://www.repostatus.org/#wip">
@@ -51,7 +51,7 @@
 
 ### Requirements
 
-- Python 3.9+
+- Python 3.10+
 
 ### Install
 

pyproject.toml

@@ -47,7 +47,7 @@ namespace = true
 [tool.mypy]
 files = "openfeature,tests/typechecking"
 
-python_version = "3.9" # should be identical to the minimum supported version
+python_version = "3.10" # should be identical to the minimum supported version
 namespace_packages = true
 explicit_package_bases = true
 local_partial_types = true # will become the new default from version 2