Drop support for python3.9

We are using functionality from importlib.resource that arrived in
version 3.10. As support for 3.9 will soon(ish) stop, lets not do
anything special.

Author: php1ic

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        python-version: ['3.10', '3.11', '3.12', '3.13']
 
     steps:
     - uses: actions/checkout@v4

pyproject.toml

@@ -10,7 +10,7 @@ authors = [
 description = "A python package to parse and store the various files published by AME and NUBASE"
 version = "0.0.1"
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 classifiers = [
   "Development Status :: 4 - Beta",
   "Intended Audience :: Education",
@@ -19,7 +19,6 @@ classifiers = [
   "Programming Language :: Python",
   "Programming Language :: Python :: 3",
   "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",