fix: correct login shell mismatch in the accept_elicitation_for_prompt_rule() test

[bolinfest]

Because the path to git is used to construct elicitations_to_accept, we need to ensure that we resolve which git to use the same way our Bash process will:

codex/codex-rs/exec-server/tests/suite/accept_elicitation.rs

Lines 59 to 69 in c9c6560

	let git_path = resolve_git_path().await?;
	let expected_elicitation_message = format!(
	"Allow agent to run `{} init .` in `{}`?",
	git_path,
	project_root_path.display()
	);
	let elicitation_requests: Arc<Mutex<Vec<CreateElicitationRequestParam>>> = Default::default();
	let client = InteractiveClient {
	elicitations_to_accept: hashset! { expected_elicitation_message.clone() },
	elicitation_requests: elicitation_requests.clone(),
	};

This fixes an issue when running the test on macOS using Bazel (#8875) where the login shell chose /opt/homebrew/bin/git whereas the non-login shell chose /usr/bin/git.