Use dotnet SDK 8.0 base image

Dockerfile

@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/core/sdk as builder
+FROM mcr.microsoft.com/dotnet/sdk:8.0 as builder
 
 ENV DOTNET_CLI_TELEMETRY_OPTOUT 1
 
@@ -45,7 +45,7 @@ RUN for ruleset in \
         && rm -rf ruleset \
     ; done
 
-FROM mcr.microsoft.com/dotnet/core/runtime
+FROM mcr.microsoft.com/dotnet/runtime:8.0
 
 RUN apt-get update \
     && apt-get -y install --no-install-recommends \