Update docker file & github actions with custom nuget source

Author: Bardin08

.github/workflows/build_docker_image.yml

@@ -31,9 +31,7 @@ jobs:
                   password: ${{ secrets.GITHUB_TOKEN }}
 
             - name: Build and Push Docker Image
-              env:
-                  NUGET_API_KEY: ${{ secrets.NUGET_API_KEY }}  # Reference the secret
               run: |
-                  docker build -t ghcr.io/bardin08/trumpee-gateway:${{ github.event.release.tag_name}} --build-arg NUGET_API_KEY=$NUGET_API_KEY .
+                  docker build -t ghcr.io/bardin08/trumpee-gateway:${{ github.event.release.tag_name}} --build-arg ${{ secrets.NUGET_API_KEY }} .
                   docker tag ghcr.io/bardin08/trumpee-gateway:${{ github.event.release.tag_name}} ghcr.io/bardin08/trumpee-gateway:latest
                   docker push ghcr.io/bardin08/trumpee-gateway --all-tags 

Dockerfile

@@ -3,7 +3,6 @@ FROM mcr.microsoft.com/dotnet/sdk:8.0-alpine AS build-env
 WORKDIR /src
 
 ARG NUGET_API_KEY
-ENV NUGET_API_KEY=$NUGET_API_KEY
 
 # Copy the project files first for better layer caching (if only code changes)
 COPY *.sln ./