Correct the docs

library/Hasql/Private/Decoders.hs

@@ -206,7 +206,7 @@ numeric = Value (Value.decoder (const A.numeric))
 
 {-|
 Decoder of the @CHAR@ values.
-Note that it supports UTF-8 values.
+Note that it supports Unicode values.
 -}
 {-# INLINABLE char #-}
 char :: Value Char

library/Hasql/Private/Encoders.hs

@@ -166,7 +166,7 @@ numeric = Value (Value.unsafePTIWithShow PTI.numeric (const A.numeric))
 {-|
 Encoder of @CHAR@ values.
 
-Note that it supports UTF-8 values and
+Note that it supports Unicode values and
 identifies itself under the @TEXT@ OID because of that.
 -}
 {-# INLINABLE char #-}