fix: revert to python:3.10-slim base image for AutoGen Studio (#5932)

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## Why are these changes needed?

This reverts the base image in AutoGen Studio Dockerfile to `FROM
python:3.10-slim`. This fixes the Docker image build failure due to
conflicting UID with Dev Container's `vscode` user.

## Related issue number

Fixes #5929

## Checks

- [ ] I've included any doc changes needed for
<https://microsoft.github.io/autogen/>. See
<https://github.com/microsoft/autogen/blob/main/CONTRIBUTING.md> to
build and test documentation locally.
- [ ] I've added tests (if relevant) corresponding to the changes
introduced in this PR.
- [ ] I've made sure all auto checks have passed.

python/packages/autogen-core/docs/src/user-guide/autogenstudio-user-guide/faq.md

@@ -165,7 +165,7 @@ team = BaseGroupChat.load_component(team_config)
 A: Yes, you can run AutoGen Studio in a Docker container. You can build the Docker image using the provided [Dockerfile](https://github.com/microsoft/autogen/blob/autogenstudio/samples/apps/autogen-studio/Dockerfile) and run the container using the following commands:
 
 ```bash
-FROM python:3.10
+FROM python:3.10-slim
 
 WORKDIR /code
 

python/packages/autogen-studio/Dockerfile

@@ -1,9 +1,9 @@
-FROM mcr.microsoft.com/devcontainers/python:3.10
-
+FROM python:3.10-slim
 WORKDIR /code
 
 RUN pip install -U gunicorn autogenstudio
 
+# Create a non-root user
 RUN useradd -m -u 1000 user
 USER user
 ENV HOME=/home/user \

python/packages/autogen-studio/frontend/src/components/views/deploy/guides/docker.tsx

@@ -31,7 +31,7 @@ const DockerGuide: React.FC = () => {
           </a>
           that you can use to build your Docker container.{" "}
         </div>
-        code={`FROM mcr.microsoft.com/devcontainers/python:3.10
+        code={`FROM python:3.10-slim
 
 WORKDIR /code
 
@@ -56,7 +56,7 @@ CMD gunicorn -w $((2 * $(getconf _NPROCESSORS_ONLN) + 1)) --timeout 12600 -k uvi
         title="2. Build and Run"
         description="Build and run your Docker container:"
         code={`docker build -t autogenstudio .
-docker run -p 8000:8000 autogenstudio`}
+docker run -p 8081:8081 autogenstudio`}
         onCopy={copyToClipboard}
       />
     </div>