Update Dockerfile

Author: danielgerlag

reactions/azure/eventgrid-reaction/Dockerfile

@@ -13,14 +13,14 @@
 # limitations under the License.
 
 
-FROM mcr.microsoft.com/dotnet/sdk:8.0-cbl-mariner2.0 AS build
+FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:8.0-cbl-mariner2.0 AS build
 ARG BUILD_CONFIGURATION=Release
 WORKDIR /src
 COPY . .
 RUN dotnet restore
 RUN dotnet build -c $BUILD_CONFIGURATION -o /app/build
 
-FROM mcr.microsoft.com/dotnet/aspnet:8.0-cbl-mariner2.0 AS final
+FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/aspnet:8.0-cbl-mariner2.0 AS final
 WORKDIR /app
 COPY --from=build /app/build .
-ENTRYPOINT ["/app/eventgrid-reaction"]
+ENTRYPOINT ["/app/eventgrid-reaction"]