chore: drop Python 3.9 support [BREAKING CHANGE]

Author: sjakthol

.github/workflows/python_ci.yaml

@@ -12,7 +12,7 @@ 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@v6

pyproject.toml

@@ -1,13 +1,13 @@
 [project]
 name = "aws-sqs-batchlib"
-version = "3.0.0"
+version = "3.1.0"
 description = "Library for working with Amazon SQS"
 authors = [
     { name = "Sami Jaktholm", email = "sjakthol@outlook.com" }
 ]
 license = "MIT"
 readme = 'README.md'
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
   "boto3<2"
 ]