fix: Disable asserts that rely on timing characteristics during coverage testing

constant-time/Cargo.toml

@@ -20,3 +20,6 @@ memsec = { workspace = true }
 
 [dev-dependencies]
 rand = "0.8.5"
+
+[lints.rust]
+unexpected_cfgs = { level = "allow", check-cfg = ['cfg(coverage)'] }

constant-time/src/memcmp.rs

@@ -113,9 +113,10 @@ mod tests {
         // Pearson correlation
         let correlation = cv / (sd_x * sd_y);
         println!("correlation: {:.6?}", correlation);
+        #[cfg(not(coverage))]
         assert!(
             correlation.abs() < 0.01,
             "execution time correlates with result"
-        )
+        );
     }
 }