move the remove variable sysmbols function to utils

src/include/builtins.h

@@ -62,11 +62,4 @@ void set_variable(StringArray *args);
  */
 void echo(StringArray *args);
 
-/**
- * Remove the $ symbol from a variable name.
- * @param original_variable The original variable name.
- * @return Returns the string without the $ symbool.
- */
-char *remove_variable_symbol(char *original_variable);
-
 #endif

src/include/utils.h

@@ -27,4 +27,12 @@ void remove_new_line(char *line);
  * @return Returns the current working directory.
  */
 char *get_working_directory();
+
+/**
+ * Remove the $ symbol from a variable name.
+ * @param original_variable The original variable name.
+ * @return Returns the string without the $ symbool.
+ */
+char *remove_variable_symbol(char *original_variable);
+
 #endif