devcontainer: Use aws ecr registry instead of docker registry

Get the ubuntu base image from public aws ecr instead of docker
registry. In addition:

* Upgrade to ubuntu 22.04 from 20.04 because the eol for ubuntu 20.04
  is 04/2025.
* Python3.9 package is removed as it is not needed anymore. The
  python3.9 workaround required for VSI is handled as part of
  `tools/scripts/setup_python_vsi.sh`
* Python 3.10 built from source is removed as it comes pre-installed
  with ubuntu 22.04
* Build and install uncrustify 0.69.0 as the version packaged with
  ubuntu 22.04 is higher than intended
* Added vim configuration (~/.vimrc) to enable spell check in vim

Signed-off-by: Devaraj Ranganna <devaraj.ranganna@arm.com>