K2: don't make T = Type! substitutions for constructors, including SAM

Without this commit we get some ABI changes and it looks bad.

Related to KT-65596

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/interconnectedGenerics.fir.txt

@@ -34,7 +34,7 @@ FILE: Eq.kt
             public get(): R|lib/a/A<R, S>|
 
         public open override fun withL(l: R|kotlin/Int|): R|lib/a/C.WithL<R, S>| {
-            ^withL Q|lib/a/C|.R|lib/a/C.MyWithL.MyWithL|<R|R!|, R|S!|>()
+            ^withL Q|lib/a/C|.R|lib/a/C.MyWithL.MyWithL|<R|R|, R|S|>()
         }
 
     }