Modernize GitHub Actions test runner

.appveyor.yml

@@ -5,10 +5,9 @@
 # This is slow, try to keep the number of builds as low as makes sense.
 
 image:
-  # linux builds done in Travis CI for now
+  # Test images unsupported by GitHub Actions.
   - Visual Studio 2017
   - Visual Studio 2019
-  - Visual Studio 2022
 
 cache:
   - downloads -> appveyor.yml
@@ -19,8 +18,8 @@ cache:
 install:
   # direct choco install supposed to work, but not? still doing in install.bat
   #- cinst: dmd ldc swig vswhere ixsltproc winflexbison3
-  - cmd: .\.appveyor\install.bat
-  - cmd: if %COVERAGE% equ 1 .\.appveyor\install-cov.bat
+  - ps: .\.appveyor\install.ps1
+  - ps: if ($env:COVERAGE -eq 1) { .\.appveyor\install-cov.ps1 }
 
 # Build matrix will be number of images multiplied by #entries in matrix:,
 # less any excludes.
@@ -34,38 +33,9 @@ environment:
   COVERAGE: 0
   SCONS_CACHE_MSVC_CONFIG: "true"
   matrix:
-    # Test oldest and newest supported Pythons, and a subset in between.
-    # Skipping 3.8, 3.10, 3.12 at this time
-    - WINPYTHON: "Python313"
-    - WINPYTHON: "Python311"
-    - WINPYTHON: "Python39"
-    - WINPYTHON: "Python37"
-
-# remove sets of build jobs based on criteria below
-# to fine tune the number and platforms tested
-matrix:
-  exclude:
-    # test python 3.7 on Visual Studio 2017 image
-    - image: Visual Studio 2017
-      WINPYTHON: "Python313"
-    - image: Visual Studio 2017
-      WINPYTHON: "Python311"
-    - image: Visual Studio 2017
-      WINPYTHON: "Python39"
-
-    # test python 3.9 on Visual Studio 2019 image
-    - image: Visual Studio 2019
-      WINPYTHON: "Python313"
-    - image: Visual Studio 2019
-      WINPYTHON: "Python311"
-    - image: Visual Studio 2019
-      WINPYTHON: "Python37"
-
-    # test python 3.11, 3.13 on Visual Studio 2022 image
-    - image: Visual Studio 2022
-      WINPYTHON: "Python39"
-    - image: Visual Studio 2022
-      WINPYTHON: "Python37"
+    # Test oldest and newest supported Pythons.
+    - WINPYTHON: "Python310"
+    - WINPYTHON: "Python312"
 
 # Remove some binaries we don't want to be found
 # Note this is no longer needed, git-windows bin/ is quite minimal now.

.appveyor/install-cov.ps1

@@ -0,0 +1,3 @@
+$pythonExe = "C:\$($env:WINPYTHON)\python.exe"
+$env:PYSITEDIR = & $pythonExe -c "import sys; print(sys.path[-1])"
+& $pythonExe -m pip install -U --progress-bar off coverage codecov

.appveyor/install.ps1

@@ -0,0 +1,48 @@
+$pythonExe = "C:\$($env:WINPYTHON)\python.exe"
+
+# If the initial call to python --version fails, call "choco install %WINPYTHON%"
+$pyVersionSucceeded = $false
+try {
+    if (Test-Path $pythonExe) {
+        & $pythonExe --version
+        if ($LASTEXITCODE -eq 0) {
+            $pyVersionSucceeded = $true
+        }
+    }
+} catch {
+    $pyVersionSucceeded = $false
+}
+
+if (-not $pyVersionSucceeded) {
+    Write-Host "Python version check failed or Python not found at $pythonExe. Installing $env:WINPYTHON via Chocolatey..."
+    choco install --allow-empty-checksums $env:WINPYTHON
+}
+
+# Set PYSITEDIR
+$env:PYSITEDIR = & $pythonExe -c "import sys; print(sys.path[-1])"
+
+# Use mingw 32 bit until #3291 is resolved
+# Add python and python user-base to path for pip installs
+$extraPaths = @(
+    "C:\$($env:WINPYTHON)",
+    "C:\$($env:WINPYTHON)\Scripts",
+    "C:\ProgramData\chocolatey\bin",
+    "C:\MinGW\bin",
+    "C:\MinGW\msys\1.0\bin",
+    "C:\cygwin\bin",
+    "C:\msys64\usr\bin",
+    "C:\msys64\mingw64\bin"
+)
+$env:PATH = ($extraPaths + @($env:PATH)) -join ';'
+
+# pip installs
+& $pythonExe -m pip install -U --progress-bar off pip setuptools wheel
+
+# requirements-dev.txt will skip installing lxml for windows and py 3.11+, where there's
+# no current binary wheel
+& $pythonExe -m pip install -U --progress-bar off -r requirements-dev.txt
+
+choco install --allow-empty-checksums dmd ldc swig vswhere xsltproc winflexbison3
+
+# Show environment variables
+Get-ChildItem Env: | Sort-Object Name