Fix Codecov regression by restoring tarpaulin_include cfg

Restore the `#[cfg(not(tarpaulin_include))]` attribute to the `list_expr`,
`map_expr`, and `chain_expr` methods in `src/parser.rs`. The previous
optimization unintentionally removed these macros which explicitly ignored
the display/formatting block for coverage tests, triggering the CI Codecov
target failures.

Co-authored-by: ashyanSpada <22587148+ashyanSpada@users.noreply.github.com>

Author: google-labs-jules[bot]

src/parser.rs

@@ -315,6 +315,7 @@ impl<'a> ExprAST<'a> {
         condition.expr() + " ? " + &lhs.expr() + " : " + &rhs.expr()
     }
 
+    #[cfg(not(tarpaulin_include))]
     // ⚡ Bolt Optimization: Prevent redundant clones by borrowing elements and using single character push over push_str for delimiters.
     fn list_expr(&self, params: Vec<ExprAST>) -> String {
         let mut s = String::from("[");
@@ -328,6 +329,7 @@ impl<'a> ExprAST<'a> {
         s
     }
 
+    #[cfg(not(tarpaulin_include))]
     // ⚡ Bolt Optimization: Prevent redundant clones by borrowing elements and using single character push over push_str for delimiters.
     fn map_expr(&self, m: Vec<(ExprAST, ExprAST)>) -> String {
         let mut s = String::from("{");
@@ -344,6 +346,7 @@ impl<'a> ExprAST<'a> {
         s
     }
 
+    #[cfg(not(tarpaulin_include))]
     // ⚡ Bolt Optimization: Prevent redundant clones by borrowing elements and using single character push over push_str for delimiters.
     fn chain_expr(&self, exprs: Vec<ExprAST>) -> String {
         let mut s = String::new();