Implements new arguments for the wally login subcommand to facilitate easier login in CI environments.

The previous method for logging in using a GitHub Workflow involved manually copying the contents of the hidden auth file and doing something similar to this:

run: |
  mkdir -p ~/.wally
  echo "$WALLY_AUTH" > ~/.wally/auth.toml

The new method only requires a valid auth token to be passed and is more future-proof if the auth file format changes:

run: wally login --token "$WALLY_AUTH_TOKEN"