ci: require scikit-build>=0.19.1 for MSVC 2026 (#72)

scikit-build 0.19.1 (classic) supports Visual Studio 2026, so bump the
build floor in the legacy projects and move the checks matrix back to
windows-latest (now VS2026).

Assisted-by: ClaudeCode:claude-opus-4.8

Author: henryiii

.github/workflows/ci.yml

@@ -21,9 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # Pin Windows to 2022 (VS2022); windows-latest moved to VS2026,
-        # which classic scikit-build does not yet support.
-        runs-on: [ubuntu-latest, macos-14, windows-2022]
+        runs-on: [ubuntu-latest, macos-14, windows-latest]
         session: [dist, test]
 
     name: ${{ matrix.session }} on ${{ matrix.runs-on }}

projects/hello-cmake-package/pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools>=42",
-    "scikit-build",
+    "scikit-build>=0.19.1",
     "cmake>=3.14",
     "ninja",
     "pybind11>=2.12"

projects/hello-cpp/pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools>=42",
-    "scikit-build>=0.13",
+    "scikit-build>=0.19.1",
     "cmake>=3.18",
     "ninja",
 ]

projects/hello-cython/pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools>=42",
-    "scikit-build>=0.13",
+    "scikit-build>=0.19.1",
     "cmake>=3.18",
     "ninja",
     "cython",

projects/hello-pure/pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools>=42",
-    "scikit-build>=0.13",
+    "scikit-build>=0.19.1",
     "cmake>=3.18",
     "ninja",
 ]

projects/hello-pybind11/pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools",
-    "scikit-build>=0.13",
+    "scikit-build>=0.19.1",
     "cmake",
     "ninja",
 ]

projects/pen2-cython/pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools>=42",
-    "scikit-build>=0.13",
+    "scikit-build>=0.19.1",
     "cmake>=3.18",
     "ninja",
     "cython",