Fixed tiny spelling error in NavigationAgent2D docs

[Sai-Suraj-27]

Description

Fixes #80468
Fixed the small spelling mistake in line 183 (https://github.com/godotengine/godot/blob/master/doc/classes/NavigationAgent2D.xml)

[akien-mga]

Confirmed that it's the only occurrence of a too + present participle typo in the docs:

$ rg -g'*.xml' "too [a-z]+ing"
doc/classes/NavigationAgent2D.xml
183:                    The distance threshold before a path point is considered to be reached. This allows agents to not have to hit a path point on the path exactly, but only to reach its general area. If this value is set too high, the NavigationAgent will skip points on the path, which can lead too leaving the navigation mesh. If this value is set too low, the NavigationAgent will be stuck in a repath loop because it will constantly overshoot or undershoot the distance to the next point on each physics frame update.

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉

[YuriSizov]

Will skip from cherry-picking as this would invalidate the translation of the entire description. It's an unfortunate typo, but a minor issue.