New Sagemaker Studio JupyterLab lacks Git extension and "studio" environment?

### Product Version

- [ ] Amazon SageMaker Studio Classic
- [X] Amazon SageMaker Studio
- [ ] Issue is not related to SageMaker Studio

### Issue Description

The _New_ Sagemaker Studio JupyterLab IDE lacks the essential Git extension. Also, opening a terminal within JupyterLab `conda env list` shows only one "base" environment. `conda activate studio` precipitates an error. `pip install jupyterlab-git` is possible, but a webpage refresh yields an error: "Failed to load the jupyterlab-git server extension".

### Expected Behavior

- According to AWS documentation, the JupyterLab extension for git should be preinstalled.
- There should be a conda environment named "studio" for the installation of new extensions.

### Observed Behavior

- In the New Sagemaker Studio the JupyterLab extension for git is absent.
- There is no conda environment named "studio" for the installation of new extensions.

### Product Category

JupyterLab

### Feedback Category

Configuration and Setup, GitHub Integration, User Interface

### Other Details

_No response_

No repository files or tests are mentioned. Start by reproducing the issue in a new Amazon SageMaker Studio JupyterLab environment and compare the available conda environments and Git extension behavior with the referenced AWS documentation. Done means confirming the expected preinstalled extension and studio environment, or documenting the product limitation.

Written by the indexing model from the issue text.