Update supported Python versions

- Remove Python 3.7 from the test matrix and list of supported versions
  in `setup.py`, as it reached end of life on 2023-06-27
- Add Python 3.12 to the list of tested / supported versions as the
  current major version

.github/workflows/test.yml

@@ -5,11 +5,11 @@ jobs:
     strategy:
       matrix:
         python:
-          - "3.7"
           - "3.8"
           - "3.9"
           - "3.10"
           - "3.11"
+          - "3.12"
     runs-on: ubuntu-latest
     steps:
     - name: Checkout

setup.py

@@ -44,11 +44,11 @@ def readme():
         "Operating System :: OS Independent",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: 3.12",
         "Intended Audience :: Developers",
     ],
     keywords="validate CSV vampires",