task: Check context error

Check context error after running dependencies, to prevent false
positive preconditions errors due to "context canceled".

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>

task.go

@@ -315,6 +315,10 @@ func (e *Executor) RunTask(ctx context.Context, call taskfile.Call) error {
 		}
 
 		if !e.Force {
+			if err := ctx.Err(); err != nil {
+				return err
+			}
+
 			preCondMet, err := e.areTaskPreconditionsMet(ctx, t)
 			if err != nil {
 				return err