Changed docker file from .net 7 to 8

Author: Tomasz Juszczak

Dockerfile

@@ -1,9 +1,9 @@
-FROM mcr.microsoft.com/dotnet/aspnet:7.0 AS base
+FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS base
 WORKDIR /app
 EXPOSE 80
 EXPOSE 443
 
-FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
 WORKDIR /src
 COPY ["Slack-GPT-Socket/Slack-GPT-Socket.csproj", "Slack-GPT-Socket/"]
 RUN dotnet restore "Slack-GPT-Socket/Slack-GPT-Socket.csproj"