Fix SpecializeTuples phase name capitisation

Author: dwijnand

compiler/src/dotty/tools/dotc/transform/SpecializeTuples.scala

@@ -44,5 +44,5 @@ class SpecializeTuples extends MiniPhase:
 end SpecializeTuples
 
 object SpecializeTuples:
-  val name: String = "SpecializeTuples"
+  val name: String = "specializeTuples"
   val description: String = "replaces tuple construction and selection trees"