Add Python 3.12 CI tests (#267)

Author: DimitriPapadopoulos

.github/workflows/run_unit_tests.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
         dependencies: [".", "'.[libjpeg]'"]
 
     steps: