refactor: use GHC.Num.Integer.integerLog2 in Logarithmic instance

Modernize logarithm calculation in the Logarithmic ExMemoryUsage instance
by switching from the compatibility module GHC.Integer.Logarithms to the
modern GHC.Num.Integer API.

Changes:
- Replace integerLog2# (unboxed, from GHC.Integer.Logarithms) with
  integerLog2 (boxed, from GHC.Num.Integer)
- Simplify code by removing unboxing boilerplate: I# (integerLog2# x)
  becomes integerLog2 x
- Keep other imports (GHC.Integer.Logarithms, GHC.Exts) as they are still
  used elsewhere in the file (memoryUsageInteger function)

This addresses code review feedback to use the modern ghc-bignum API
instead of the legacy compatibility module, while maintaining the same
computational semantics. Cost model regeneration verified no regression
in derived parameters.

Author: Unisay

plutus-core/plutus-core/src/PlutusCore/Evaluation/Machine/ExMemoryUsage.hs

@@ -35,11 +35,11 @@ import Data.Text qualified as T
 import Data.Vector.Strict (Vector)
 import Data.Vector.Strict qualified as Vector
 import Data.Word
-import GHC.Exts (Int (I#))
+import GHC.Exts (Int (I#), quotInt#)
 import GHC.Integer
 import GHC.Integer.Logarithms
 import GHC.Natural
-import GHC.Prim
+import GHC.Num.Integer (integerLog2)
 import Universe
 
 {-
@@ -411,7 +411,7 @@ instance ExMemoryUsage n => ExMemoryUsage (Logarithmic n) where
         CostRose size _ ->
           let sizeInteger :: Integer
               sizeInteger = fromSatInt size
-              logSize = I# (integerLog2# sizeInteger)
+              logSize = integerLog2 sizeInteger
           in singletonRose $ max 1 (fromIntegral (logSize + 1))
     {-# INLINE memoryUsage #-}