[BUG] Docker example problems on ARM64 and Mac Silicon

[c-barakat]

Tested with version 2.8.0
Trying to run the docker example on arm64 and Mac silicon systems as described in the README under examples/docker fails at multiple steps. I've documented here some of the changes that I made to the installation to be able to run the example locally, but it still fails when i try to run it on two separate machines.

Steps to reproduce the installation problems:

1. Clone the repository
2. git checkout tags/2.8.0
3. Install NVFlare pip install -e .[dev,PT]
4. You receive error ERROR: Could not find a version that satisfies the requirement tenseal==0.3.15; python_version < "3.13" and extra == "dev" (from nvflare-nightly[dev,pt]) (from versions: 0.3.17)
5. This also occurs when building the docker job image since it also tries to pip install -e .[dev,MONITORING,PT]

Expected behavior:
The example should work out of the box or the README should reflect the necessary changes depending on the architecture.

Desktop:

• OS: Ubuntu 24.04.4 LTS
• Python Version 3.12.13
• NVFlare Version 2.8.0

Additional context:
Above are only issues related to setting up the example.
However, when running the PyTorch example, further issues arise:

• After running nvflare job submit jobs/hello-pt-docker --startup-kit path/to/startup/kit you will get ERRNO13: Permission denied as torchvision tries to download and extract the cifar10 dataset.
• This is resolved by adding the following to both dockerfiles:

  RUN useradd --badname 1000
  RUN mkdir -p /var/tmp/nvflare && chmod -R 1777 /var/tmp/nvflare 
  

• With these changes, this example will run locally but when trying to run between two machines another Permission denied issue appears RuntimeError: cannot connect to Docker daemon: Error while fetching server API version: ('Connection aborted.', PermissionError(13, 'Permission denied'))
• As of this moment, I still cannot locate this issue and would appreciate any pointers as to how to resolve it or where to begin.