fix(ci): split CMake and dotnet build steps for MSYS2 path issue

- Run CMake configure+compile in msys2 shell (needs MinGW cmake on PATH)
- Run dotnet build in default shell (needs .NET SDK on PATH)
- Add BuildNativeDll=false property to skip CMake when already built
- Fix 'dotnet: command not found' in MSYS2 shell

Author: StArraySharp

.github/workflows/build.yml

@@ -70,9 +70,15 @@ jobs:
         with:
           dotnet-version: '10.0.x'
 
-      - name: Build (native + C#)
+      - name: Build Native (CMake + MinGW)
         shell: msys2 {0}
-        run: dotnet build StArray.ModManager.Windows/StArray.ModManager.Windows.csproj -c Release
+        run: |
+          cd StArray.ModManager.Windows/Native
+          cmake -B build -G "MinGW Makefiles" -DCMAKE_BUILD_TYPE=Release
+          cmake --build build
+
+      - name: Build C#
+        run: dotnet build StArray.ModManager.Windows/StArray.ModManager.Windows.csproj -c Release -p:BuildNativeDll=false
 
       - name: Package
         run: |

StArray.ModManager.Windows/StArray.ModManager.Windows.csproj

@@ -30,7 +30,7 @@
     </Content>
   </ItemGroup>
 
-  <Target Name="BuildNativeDll" BeforeTargets="BeforeBuild">
+  <Target Name="BuildNativeDll" BeforeTargets="BeforeBuild" Condition="'$(BuildNativeDll)' != 'false'">
     <Exec Command="cmake -B &quot;$(ProjectDir)Native\build&quot; -G &quot;MinGW Makefiles&quot; -DCMAKE_BUILD_TYPE=$(Configuration)"
           WorkingDirectory="$(ProjectDir)Native" />
     <Exec Command="cmake --build &quot;$(ProjectDir)Native\build&quot;"