ignore the robot magic filesystem with install, and small /bin/sleep fix

/bin/sleep ^c was printing an error because it was returning the event data, which prompts was interpretting as error details [unexpected]
use a .prop file to have the robot component magic fs be ignored when running `install`

src/main/resources/assets/opencomputers/loot/openos/bin/sleep.lua

@@ -53,7 +53,7 @@ end
 
 local stdin_stream = io.stdin.stream
 if stdin_stream.pull then
-  return stdin_stream:pull(nil, total_time, "interrupted")
+  stdin_stream:pull(nil, total_time, "interrupted")
 else
-  os.sleep(total_time)
+  require("event").pull(total_time, "interrupted")
 end

src/main/resources/assets/opencomputers/lua/component/robot/.prop

@@ -0,0 +1 @@
+{ignore=true}