feat: Close the smallest pendulum configuration-space sorryful definitions

[NicolaBernini]

Overview

Close the smallest pendulum configuration-space sorryful definitions

[github-actions]

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[jstoobysmith]

I think I would make this [Real.Angle](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.html#Real.Angle) rather then Real.