package/ci: use Python 3.8 instead of 3.7 on MSVC 2019 and 2022.

It's not on AppVeyor anymore. Unfortunately I have no idea when that
happened, since I last built this repo there in May 2025.

package/ci/appveyor.yml

@@ -12,28 +12,28 @@ environment:
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-msvc2019
-    # Python 3.6 was removed from 2019 and 2022 images in Dec 2023
-    PYTHON: 7
+    # Python 3.7 was removed from 2019 and 2022 images sometimes in 2025
+    PYTHON: 8
     PYBIND: 2.3.0
   - TARGET: desktop
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     APPVEYOR_JOB_NAME: windows-msvc2022
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.9.0 # first supporting MSVC 2022
   - TARGET: desktop
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-static-msvc2019
     BUILD_STATIC: ON
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.3.0
   - TARGET: desktop
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     APPVEYOR_JOB_NAME: windows-static-msvc2022
     BUILD_STATIC: ON
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.9.0 # first supporting MSVC 2022
   # clang-cl crashes with pybind11, "Illegal instruction" and
   #   lld-link: warning: ignoring unknown argument '-flto'
@@ -43,13 +43,13 @@ environment:
     #COMPILER: msvc-clang
     #APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     #APPVEYOR_JOB_NAME: windows-msvc2019-clang
-    #PYTHON: 7
+    #PYTHON: 8
     #PYBIND: 2.7.0
   #- TARGET: desktop
     #COMPILER: msvc-clang
     #APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     #APPVEYOR_JOB_NAME: windows-msvc2022-clang
-    #PYTHON: 7
+    #PYTHON: 8
     #PYBIND: 2.9.0 # first supporting MSVC 2022
   - TARGET: desktop
     COMPILER: msvc
@@ -57,7 +57,7 @@ environment:
     COMPILER_EXTRA: -DCMAKE_CXX_FLAGS="/permissive- /EHsc" -DCORRADE_MSVC_COMPATIBILITY=OFF
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-conforming-msvc2019
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.3.0
   - TARGET: desktop
     COMPILER: msvc
@@ -65,35 +65,35 @@ environment:
     COMPILER_EXTRA: -DCMAKE_CXX_FLAGS="/permissive- /EHsc" -DCORRADE_MSVC_COMPATIBILITY=OFF
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     APPVEYOR_JOB_NAME: windows-conforming-msvc2022
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.9.0 # first supporting MSVC 2022
   - TARGET: desktop-gles
     TARGET_GLES2: ON
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-gles2-msvc2019
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.3.0
   - TARGET: desktop-gles
     TARGET_GLES2: ON
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     APPVEYOR_JOB_NAME: windows-gles2-msvc2022
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.9.0 # first supporting MSVC 2022
   - TARGET: desktop-gles
     TARGET_GLES2: OFF
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-gles3-msvc2019
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.3.0
   - TARGET: desktop-gles
     TARGET_GLES2: OFF
     COMPILER: msvc
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     APPVEYOR_JOB_NAME: windows-gles3-msvc2022
-    PYTHON: 7
+    PYTHON: 8
     PYBIND: 2.9.0 # first supporting MSVC 2022
 
 install: