fix(ci): use python 3.8 instead of python 3.7 to check sdist (scikit-build#549)

Author: mayeut

.github/workflows/build.yml

@@ -180,7 +180,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python: ["3.7", "3.13"]
+        python: ["3.8", "3.13"]
 
     steps:
       - uses: actions/checkout@v4