[ksqlDB.RestApi.Client]: upgraded Connect.SqlServer to dotnet 9

Author: tomasfabian

Samples/Connect/SqlServer/Connect.SqlServer.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
       <OutputType>Exe</OutputType>
-      <TargetFramework>net8.0</TargetFramework>
+      <TargetFramework>net9.0</TargetFramework>
       <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>
       <DockerfileContext>.</DockerfileContext>
       <LangVersion>10.0</LangVersion>

Samples/Connect/SqlServer/Dockerfile

@@ -1,9 +1,9 @@
 #See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.
 
-FROM mcr.microsoft.com/dotnet/runtime:8.0 AS base
+FROM mcr.microsoft.com/dotnet/runtime:9.0 AS base
 WORKDIR /app
 
-FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
+FROM mcr.microsoft.com/dotnet/sdk:9.0 AS build
 WORKDIR /src
 COPY ["SqlServer/Connect.SqlServer.csproj", "SqlServer/"]
 COPY ["../../SqlServer.Connector/SqlServer.Connector.csproj", "../../SqlServer.Connector/"]