kragen-flask-server docker image size is large

**Describe the bug**
When building the kragen-flask-server docker image, the size of the image is 9.35GB.

**To Reproduce**
Steps to reproduce the behavior:
1. At the step in the instructions to run `./kragen-gui.sh`, the script runs and builds the kragen-flask-server docker image
2. The docker image seems to run correctly, but the size is 9.35GB.
3. `docker history` shows that the graph_of_thoughts layer is 8.78GB in size:

```
> IMAGE CREATED CREATED BY SIZE COMMENT
> 1426e8c6dc8b 39 minutes ago CMD ["python" "execgpt.py"] 0B buildkit.dockerfile.v0
> 39 minutes ago EXPOSE map[5050/tcp:{}] 0B buildkit.dockerfile.v0
> 39 minutes ago RUN /bin/sh -c flask --app ExecGPTServer ini… 817kB buildkit.dockerfile.v0
> 39 minutes ago RUN /bin/sh -c pip install -e graph_of_thoug… 8.78GB buildkit.dockerfile.v0
> 52 minutes ago RUN /bin/sh -c pip install -r ./ExecGPTServe… 87.3MB buildkit.dockerfile.v0
> 53 minutes ago RUN /bin/sh -c apt update --fix-missing … 342MB buildkit.dockerfile.v0
> 53 minutes ago COPY . /app # buildkit 297kB buildkit.dockerfile.v0
> 53 minutes ago WORKDIR /app 0B buildkit.dockerfile.v0
> 2 weeks ago CMD ["python3"] 0B buildkit.dockerfile.v0
> 2 weeks ago RUN /bin/sh -c set -eux; savedAptMark="$(a… 12.2MB buildkit.dockerfile.v0
> 2 weeks ago ENV PYTHON_GET_PIP_SHA256=dfe9fd5c28dc98b5ac… 0B buildkit.dockerfile.v0
> 2 weeks ago ENV PYTHON_GET_PIP_URL=https://github.com/py… 0B buildkit.dockerfile.v0
> 2 weeks ago ENV PYTHON_SETUPTOOLS_VERSION=65.5.1 0B buildkit.dockerfile.v0
> 2 weeks ago ENV PYTHON_PIP_VERSION=23.0.1 0B buildkit.dockerfile.v0
> 2 weeks ago RUN /bin/sh -c set -eux; for src in idle3 p… 32B buildkit.dockerfile.v0
> 2 weeks ago RUN /bin/sh -c set -eux; savedAptMark="$(a… 31.9MB buildkit.dockerfile.v0
> 2 weeks ago ENV PYTHON_VERSION=3.10.14 0B buildkit.dockerfile.v0
> 2 weeks ago ENV GPG_KEY=A035C8C19219BA821ECEA86B64E628F8… 0B buildkit.dockerfile.v0
> 2 weeks ago RUN /bin/sh -c set -eux; apt-get update; a… 9.23MB buildkit.dockerfile.v0
> 2 weeks ago ENV LANG=C.UTF-8 0B buildkit.dockerfile.v0
> 2 weeks ago ENV PATH=/usr/local/bin:/usr/local/sbin:/usr… 0B buildkit.dockerfile.v0
> 25 hours ago /bin/sh -c #(nop) CMD ["bash"] 0B
> 25 hours ago /bin/sh -c #(nop) ADD file:d4bb05cb4d403a78b… 74.8MB
```

**Expected behavior**
The image size should be of a reasonable size, 2 other users have reported that the image size on their systems (Ubuntu and Mac) are about 2GB in size.

**Desktop (please complete the following information):**
- OS: Arch Linux (release 2024.04.01) and WSL2 running Ubuntu 22.04.4 LTS

**Additional context**
Although the image and container appear to be functional, this may be an issue for other users. So, this issue may need further investigation (perhaps on different platforms)