ci python 3.15 beta

Author: scivision

.github/workflows/ci_stdlib_only.yml

@@ -16,7 +16,8 @@ jobs:
     name: ${{ matrix.os }} Python ${{ matrix.python-version }}
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.14',
+          '3.15-dev']
         os: ['ubuntu-latest']
         include:
         - os: macos-latest