Fix Python version quoting and flake8 issues

Author: mloubout

.github/workflows/flake8.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Python 3.11
       uses: actions/setup-python@v5
       with:
-        python-version: 3.11
+        python-version: '3.11'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

.github/workflows/pytest-linux.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-20.04, ubuntu-latest]
-        python-version: [3.10, 3.11, 3.12, 3.13]
+        python-version: ['3.10', '3.11', '3.12', '3.13']
 
     steps:
     - uses: actions/checkout@v4

.github/workflows/pytest-macOS.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: macos-latest
     strategy:
       matrix:
-        python-version: [3.10, 3.11, 3.12, 3.13]
+        python-version: ['3.10', '3.11', '3.12', '3.13']
 
     steps:
     - uses: actions/checkout@v4

setup.py

@@ -55,8 +55,8 @@ def extensions():
     'author': "Imperial College London",
     'author_email': 'g.gorman@imperial.ac.uk',
     'license': 'MIT',
-    'zip_safe': False
-    ,'classifiers': [
+    'zip_safe': False,
+    'classifiers': [
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3 :: Only',
         'Programming Language :: Python :: 3.10',