cross-compile inside the container

Dockerfile

@@ -1,12 +1,12 @@
-FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build-env
+FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:8.0 AS build-env
 WORKDIR /App
 
 COPY . ./
-RUN dotnet restore
-RUN dotnet publish -c Release -o out
+RUN dotnet restore -a $TARGETARCH
+RUN dotnet publish -a $TARGETARCH -c Release -o out
 
 FROM mcr.microsoft.com/dotnet/aspnet:8.0
 WORKDIR /App
 COPY --from=build-env /App/out .
 EXPOSE 8080
-CMD ["./CarCareTracker"]
+CMD ["./CarCareTracker"]