chore: correct the usage of a legacy numeric constant

crates/aiken-lang/src/expr.rs

@@ -1337,7 +1337,7 @@ impl UntypedExpr {
         match self {
             Self::BinOp { name, .. } => name.precedence(),
             Self::PipeLine { .. } => 0,
-            _ => std::u8::MAX,
+            _ => u8::MAX,
         }
     }
 

crates/aiken-project/src/test_framework.rs

@@ -731,7 +731,7 @@ impl<'a> Counterexample<'a> {
                         let jv = self.choices[j];
 
                         // Replace
-                        if iv > 0 && jv <= u8::max_value() - iv {
+                        if iv > 0 && jv <= u8::MAX - iv {
                             self.binary_search_replace(0, iv, |v| vec![(i, v), (j, jv + (iv - v))]);
                         }