chore: fix implicit-reducible diamond in Schwartz space (leanprover-community#38263)

Co-authored-by: sgouezel <sebastien.gouezel@univ-rennes1.fr>

Author: sgouezel

Mathlib/Analysis/Distribution/SchwartzSpace/Basic.lean

@@ -530,7 +530,7 @@ instance instIsTopologicalAddGroup : IsTopologicalAddGroup 𝓢(E, F) :=
   (schwartzSeminormFamily ℝ E F).addGroupFilterBasis.isTopologicalAddGroup
 
 instance instUniformSpace : UniformSpace 𝓢(E, F) :=
-  (schwartzSeminormFamily ℝ E F).addGroupFilterBasis.uniformSpace
+  fast_instance% (schwartzSeminormFamily ℝ E F).addGroupFilterBasis.uniformSpace
 
 instance instIsUniformAddGroup : IsUniformAddGroup 𝓢(E, F) :=
   (schwartzSeminormFamily ℝ E F).addGroupFilterBasis.isUniformAddGroup