devcontainer cli - support --sig-proxy=false

[jsamuel1]

What is the problem you're trying to solve?.
Running @devcontainer/cli to launch a devcontainer, the process fails at the run step due to devcontainer/cli passing the option --sig-proxy=false to the run action when running a single container.

[4483 ms] Start: Run: finch run --sig-proxy=false -a STDOUT -a STDERR --mount type=bind,source=XXXXXXXX,target=/workspaces/XXXXXXXXX,consistency=cached -l devcontainer.local_folder=XXXXXXXX -l devcontainer.config_file=XXXXXXXX/.devcontainer/devcontainer.json -e NODE_OPTIONS=--max-old-space-size=8192 --cap-add=SYS_ADMIN --entrypoint /bin/sh vsc-xxxxxxxxxxxxxxxxxx -c echo Container started
FATA[0000] unknown flag: --sig-proxy
FATA[0001] exit status 1

Describe the feature you'd like
Would like the option to either be support or ignored.

Additional context
https://github.com/devcontainers/cli/blob/f7d4c853bf8c284d784173f3e915a34d961b0b55/src/spec-node/singleContainer.ts#L396

Reproducing steps:
From a project with a .devcontainer folder/setup that has a single Dockerfile and devcontainer.json,
run:
npx devcontainer up --docker-path finch --docker-compose-path "finch compose" --workspace-folder .

[jsamuel1]

devcontainer --version
0.55.0

[jsamuel1]

Note the -- the sig-proxy=false argument is to prevent signals (eg. Ctrl-C) being sent along to the process inside the container. Default was to pass the signal in.

[jsamuel1]

Corresponding item in vscode devcontainer extension issues: microsoft/vscode-remote-release#6014

Note - this linked issue is for the extension, not the base devcontainer packages.