Specify port 80 in Dockerfile after .NET 8 upgrade (#657)

#649
Connection to replicas fail after .NET 8 upgrade.
Assumed to be because of the following breaking change in .NET 8 images:

> The default ASP.NET Core port configured in .NET container images has been updated from port 80 to 8080.

Updated Dockerfile to specify port 80 using new environment variable ASPNETCORE_HTTP_PORTS

Co-authored-by: Jon Kjetil Øye <acn-joye@ai-dev.no>

Dockerfile

@@ -22,6 +22,7 @@ WORKDIR /app
 # ENV DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=false \
 #     DOTNET_RUNNING_IN_CONTAINER=true
 ENV ASPNETCORE_ENVIRONMENT = Development
+ENV ASPNETCORE_HTTP_PORTS = 80
 RUN apk add --no-cache icu-libs krb5-libs libgcc libintl libssl1.1 libstdc++ zlib
 
 COPY --from=generate-accessmanagement-backend /app_output .