Performed valve adjustment - unknown spring

Hello all!

First of all, I wanna thank y'all for all the information and knowledge you guys have provided on this forum. I was able to utilize it all to execute my first ever valve adjustment on my
2016 D675.

The majority of the process has been a success so far. My intake valves were still within spec on the looser side. While my exhaust valves were all out of spec on the tighter side by ~.02mm. After re-shimming, my exhaust valves are now in spec on the looser end, around .355-.375mm. All timing marks lined up nicely once the cam ladder was put back in and after some turns of the crankshaft.

In the process of putting my cam cover back, I noticed a tiny spring sitting in the crevice of my throttle body (exact location pictured). I have no idea where it came from. I was super happy that a major job was about to go without any hiccups but then this pops up. I tried retracing my steps to see where it could've came loose from but I am completely stumped.

The spring is dry. No signs of oil. I'm thinking it must've been from the throttle body unit but I'm not sure where since I didn't remove the throttle body for this procedure. I only removed the bracket that holds the throttle cables.

Any idea where this could've came from?