Parallel ignores concurrency and dependencies, we don't need to valid…

…ate (#5191)

Co-authored-by: Greg Soltis <Greg Soltis>

cli/internal/run/run.go

@@ -474,9 +474,13 @@ func buildTaskGraphEngine(
 		return nil, fmt.Errorf("Invalid task dependency graph:\n%v", err)
 	}
 
-	// Check that no tasks would be blocked by a persistent task
-	if err := engine.ValidatePersistentDependencies(g, rs.Opts.runOpts.Concurrency); err != nil {
-		return nil, fmt.Errorf("Invalid persistent task configuration:\n%v", err)
+	// Check that no tasks would be blocked by a persistent task. Note that the
+	// parallel flag ignores both concurrency and dependencies, so in that scenario
+	// we don't need to validate.
+	if !rs.Opts.runOpts.Parallel {
+		if err := engine.ValidatePersistentDependencies(g, rs.Opts.runOpts.Concurrency); err != nil {
+			return nil, fmt.Errorf("Invalid persistent task configuration:\n%v", err)
+		}
 	}
 
 	return engine, nil