specify a correct branch in ci action

Author: imryche

.github/workflows/ci.yml

@@ -2,9 +2,9 @@ name: Run tests
 
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
-    branches: [master]
+    branches: [main]
 
 jobs:
   build:
@@ -14,6 +14,7 @@ jobs:
         python-version:
           - "3.11"
           - "3.12"
+          - "3.13"
 
     steps:
       - uses: actions/checkout@v4