No feedback when an error occurs in the server in certain cases

[dhruvmanila]

With the way the tracing system is set in the server, there's no feedback provided to the user if an error occurs in certain cases. This is the case because for every tracing::error expression, we also require to send a request to display the message like:

ruff/crates/ruff_server/src/server/api/requests/execute_command.rs

Lines 129 to 130 in 7571da8

	tracing::error!("Failed to apply workspace edit: {reason}");
	show_err_msg!("Ruff was unable to apply edits: {reason}");

But, it's missing in a few cases. For example, if the path specified in ruff.configuration is invalid, the user won't know that:

ruff/crates/ruff_server/src/session/index/ruff_settings.rs

Lines 288 to 291 in 7571da8

	Err(err) => {
	tracing::error!("Unable to find editor-specified configuration file: {err}");
	editor_configuration
	}

Related to #12523

[dhruvmanila]

I looked at this and I think the reason this error message isn't displayed is because this code gets executed many number of times while building the settings index. We could either introduce a macro like show_err_msg_once but the logs would still contain multiple entries.