package/ci: work around too new CMake used with old pybind11 on Windows.

Eventually I should probably bump the min version to something newer
than 2.3, but the min version is bumped to CMake 3.5 only in 2.11 that
got released in 2023. That's too new.

package/ci/appveyor-desktop-gles.bat

@@ -3,11 +3,15 @@ if "%APPVEYOR_BUILD_WORKER_IMAGE%" == "Visual Studio 2019" call "C:/Program File
 if "%APPVEYOR_BUILD_WORKER_IMAGE%" == "Visual Studio 2017" call "C:/Program Files (x86)/Microsoft Visual Studio/2017/Community/VC/Auxiliary/Build/vcvarsall.bat" x64 || exit /b
 set PATH=%APPVEYOR_BUILD_FOLDER%\deps\bin;%PATH%
 
-rem Build pybind11. Downloaded in the appveyor.yml script.
+rem Build pybind11. Downloaded in the appveyor.yml script. Forcing
+rem -DCMAKE_POLICY_VERSION_MINIMUM=3.5 because it's bumped from 3.4 to 3.5 only
+rem in version 2.11, which got released in 2023, years after the MSVC versions
+rem we test for.
 cd pybind11-%PYBIND% || exit /b
 mkdir -p build && cd build || exit /b
 cmake .. ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5 ^
     -DPYBIND11_PYTHON_VERSION=3.%PYTHON% ^
     -DPYBIND11_TEST=OFF ^
     -G Ninja || exit /b
@@ -94,11 +98,13 @@ cmake --build . || exit /b
 cmake --build . --target install || exit /b
 cd .. && cd ..
 
-rem Build
+rem Build. Again forcing -DCMAKE_POLICY_VERSION_MINIMUM=3.5 because the
+rem pybind11 CMake config files also require just 3.4 now.
 mkdir build && cd build || exit /b
 cmake .. ^
     -DCMAKE_BUILD_TYPE=Release ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5 ^
     -DPYBIND11_PYTHON_VERSION=3.%PYTHON% ^
     -DMAGNUM_WITH_PYTHON=ON ^
     -DMAGNUM_BUILD_TESTS=ON ^

package/ci/appveyor-desktop.bat

@@ -15,11 +15,15 @@ if "%COMPILER%" == "msvc-clang" if "%APPVEYOR_BUILD_WORKER_IMAGE%" == "Visual St
 set EXCEPT_MSVC2017=ON
 IF "%APPVEYOR_BUILD_WORKER_IMAGE%" == "Visual Studio 2017" set EXCEPT_MSVC2017=OFF
 
-rem Build pybind11. Downloaded in the appveyor.yml script.
+rem Build pybind11. Downloaded in the appveyor.yml script. Forcing
+rem -DCMAKE_POLICY_VERSION_MINIMUM=3.5 because it's bumped from 3.4 to 3.5 only
+rem in version 2.11, which got released in 2023, years after the MSVC versions
+rem we test for.
 cd pybind11-%PYBIND% || exit /b
 mkdir -p build && cd build || exit /b
 cmake .. ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5 ^
     -DPYBIND11_PYTHON_VERSION=3.%PYTHON% ^
     -DPYBIND11_TEST=OFF ^
     -G Ninja || exit /b
@@ -104,12 +108,14 @@ cmake --build . || exit /b
 cmake --build . --target install || exit /b
 cd .. && cd ..
 
-rem Build
+rem Build. Again forcing -DCMAKE_POLICY_VERSION_MINIMUM=3.5 because the
+rem pybind11 CMake config files also require just 3.4 now.
 mkdir build && cd build || exit /b
 cmake .. ^
     -DCMAKE_BUILD_TYPE=Release ^
     -DCMAKE_INSTALL_PREFIX=%APPVEYOR_BUILD_FOLDER%/deps ^
     -DCMAKE_PREFIX_PATH=%APPVEYOR_BUILD_FOLDER%/SDL ^
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5 ^
     -DPYBIND11_PYTHON_VERSION=3.%PYTHON% ^
     -DMAGNUM_WITH_PYTHON=ON ^
     -DMAGNUM_BUILD_TESTS=ON ^