Add additional detailed warning message if no tasks were run. (vercel…

…#2778)

This is a quality of life improvement output log so that you don't have to tease it out from the overall run summary and the situation is more-apparent.

cli/internal/run/run_state.go

@@ -145,6 +145,11 @@ func (r *RunState) Close(terminal cli.Ui, filename string) error {
 	if r.Cached == r.Attempted && r.Attempted > 0 {
 		maybeFullTurbo = ui.Rainbow(">>> FULL TURBO")
 	}
+
+	if r.Attempted == 0 {
+		terminal.Output("") // Clear the line
+		terminal.Warn("No tasks were executed as part of this run.")
+	}
 	terminal.Output("") // Clear the line
 	terminal.Output(util.Sprintf("${BOLD} Tasks:${BOLD_GREEN}    %v successful${RESET}${GRAY}, %v total${RESET}", r.Cached+r.Success, r.Attempted))
 	terminal.Output(util.Sprintf("${BOLD}Cached:    %v cached${RESET}${GRAY}, %v total${RESET}", r.Cached, r.Attempted))