Bump base python to 3.13

As I get odd mypy errors with 3.12 and the target for this library is
3.14.

Author: pgjones

.github/workflows/ci.yml

@@ -19,10 +19,10 @@ jobs:
         include:
           - {name: '3.13', python: '3.13', tox: py313}
           - {name: '3.12', python: '3.12', tox: py312}
-          - {name: 'format', python: '3.12', tox: format}
-          - {name: 'mypy', python: '3.12', tox: mypy}
-          - {name: 'pep8', python: '3.12', tox: pep8}
-          - {name: 'package', python: '3.12', tox: package}
+          - {name: 'format', python: '3.13', tox: format}
+          - {name: 'mypy', python: '3.13', tox: mypy}
+          - {name: 'pep8', python: '3.13', tox: pep8}
+          - {name: 'package', python: '3.13', tox: package}
 
     steps:
       - uses: actions/checkout@v3

tox.ini

@@ -11,7 +11,7 @@ commands = pytest --cov=sql_tstring {posargs}
 passenv = DATABASE_URL
 
 [testenv:format]
-basepython = python3.12
+basepython = python3.13
 deps =
     black
     isort
@@ -20,7 +20,7 @@ commands =
     isort --check --diff src/sql_tstring/ tests/
 
 [testenv:pep8]
-basepython = python3.12
+basepython = python3.13
 deps =
     flake8
     flake8-bugbear
@@ -29,15 +29,15 @@ deps =
 commands = flake8 src/sql_tstring/ tests/
 
 [testenv:mypy]
-basepython = python3.12
+basepython = python3.13
 deps =
     mypy
     pytest
 commands =
     mypy src/sql_tstring/ tests/
 
 [testenv:package]
-basepython = python3.12
+basepython = python3.13
 deps =
     pdm
     twine