PG17 compatibility: Fix Test Failure in multi_name_lengths multi_create_table_constraints (#7726)

PG 17 Removes outer parentheses from CHECK constraints
we add them back for pg15,pg16 compatibility
e.g. change CHECK other_col >= 100 to CHECK (other_col >= 100)

Relevant PG commit:
e59fcbd712c777eb2987d7c9ad542a7e817954ec
e59fcbd712

CI link https://github.com/citusdata/citus/actions/runs/11844794788

```difft
 SELECT "Constraint", "Definition" FROM table_checks WHERE relid='public.check_example_365068'::regclass;
              Constraint              |            Definition             
 -------------------------------------+-----------------------------------
- check_example_other_col_check       | CHECK (other_col >= 100)
- check_example_other_other_col_check | CHECK (abs(other_other_col) >= 100)
+ check_example_other_col_check       | CHECK other_col >= 100
+ check_example_other_other_col_check | CHECK abs(other_other_col) >= 100
 
```

Co-authored-by: Mehmet YILMAZ <mehmet.yilmaz@microsoft.com>

src/test/regress/bin/normalize.sed

@@ -319,3 +319,8 @@ s/COPY DEFAULT only available using COPY FROM/COPY DEFAULT cannot be used with C
 s/COPY delimiter must not appear in the DEFAULT specification/COPY delimiter character must not appear in the DEFAULT specification/
 
 #endif /* PG_VERSION_NUM < PG_VERSION_17 */
+
+# PG 17 Removes outer parentheses from CHECK constraints
+# we add them back for pg15,pg16 compatibility
+# e.g. change CHECK other_col >= 100 to CHECK (other_col >= 100)
+s/\| CHECK ([a-zA-Z])(.*)/| CHECK \(\1\2\)/g