Fix off‑by‑one in dischargeCekValue variable discharge predicate
When descending into lambda bindings, the shift counter is used to determine whether a DeBruijn index points to a bound variable that should be left untouched. The original code used which could incorrectly discharge a free variable when exactly equaled the index. Changed the comparison to so a variable is only discharged when the current shift *exceeds* its DeBruijn index. This preserves free variables when equals the index and resolves the bug reported in plutus issue #7526. Testing will verify that the change does not affect existing functionality.
