CI: Add 3.13-dev

Thanks to this: actions/setup-python#150 (comment)

Author: stanislaw

.github/workflows/ci-linux.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13-dev"]
 
     steps:
     - uses: actions/checkout@v3

.github/workflows/ci-mac.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13-dev"]
 
     steps:
     - uses: actions/checkout@v3