Fix: F-string scann.

Author: dylan-sutton-chavez

compiler/src/modules/lexer/scan.rs

@@ -366,13 +366,13 @@ impl<'a> Scanner<'a> {
             self.scan_id_rest();
             let slice = &self.src[start..self.pos];
 
-            if is_string_prefix(slice)
+            if is_fstring_prefix(slice)
                 && let Some(&q) = self.src.get(self.pos)
                 && (q == b'"' || q == b'\'')
             {
-                self.pos += 1;
-                self.scan_string(q);
-                return Some((TokenType::String, self.line, start, self.pos));
+                let pe = self.pos;
+                self.start_fstring(start, pe);
+                return self.pending.pop();
             }
 
             if is_string_prefix(slice) {