fix: move SobolevInequality.lean (#14264)

* Forgot to incorporate 1 review comment from #14165

Author: fpvandoorn

Mathlib.lean

@@ -1003,6 +1003,7 @@ import Mathlib.Analysis.Fourier.FourierTransformDeriv
 import Mathlib.Analysis.Fourier.Inversion
 import Mathlib.Analysis.Fourier.PoissonSummation
 import Mathlib.Analysis.Fourier.RiemannLebesgueLemma
+import Mathlib.Analysis.FunctionalSpaces.SobolevInequality
 import Mathlib.Analysis.Hofer
 import Mathlib.Analysis.InnerProductSpace.Adjoint
 import Mathlib.Analysis.InnerProductSpace.Basic
@@ -3054,7 +3055,6 @@ import Mathlib.MeasureTheory.Integral.Pi
 import Mathlib.MeasureTheory.Integral.RieszMarkovKakutani
 import Mathlib.MeasureTheory.Integral.SetIntegral
 import Mathlib.MeasureTheory.Integral.SetToL1
-import Mathlib.MeasureTheory.Integral.SobolevInequality
 import Mathlib.MeasureTheory.Integral.TorusIntegral
 import Mathlib.MeasureTheory.Integral.VitaliCaratheodory
 import Mathlib.MeasureTheory.MeasurableSpace.Basic