[GH Action] Updated Windows runner (#84)

Updated from Windows 2019 to Windows 2025. This also made it necessary to upgrade Visual Studio to 2019 (from 2017)

Author: FlorianReimold

.github/workflows/build-windows.yml

@@ -9,8 +9,8 @@ env:
   # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
   INSTALL_PREFIX: _install
   PROJECT_NAME:   fineftp-server
-  VS_TOOLSET:     v141
-  VS_NAME:        vs2017
+  VS_TOOLSET:     v142
+  VS_NAME:        vs2019
 
 jobs:
   build-windows:
@@ -23,7 +23,7 @@ jobs:
     # The CMake configure and build commands are platform agnostic and should work equally well on Windows or Mac.
     # You can convert this to a matrix build if you need cross-platform coverage.
     # See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
-    runs-on: windows-2019
+    runs-on: windows-2025
 
     steps:
 
@@ -56,7 +56,6 @@ jobs:
       shell: cmd
       run: |
            cmake -B ${{github.workspace}}/_build ^
-                 -G "Visual Studio 16 2019" ^
                  -A ${{ matrix.build_arch }} ^
                  -T ${{ env.VS_TOOLSET }} ^
                  -DFINEFTP_SERVER_BUILD_TESTS=ON ^