[Bug]: Error on not using `withImmutableDescription()` and `withUpdatableMetadata()`

### Bug description

While trying to optionally use `withImmutableDescription()` and `withUpdatableMetadata()` an error occours:

```TS
const notarizationBuilder = notarizationClient
.createLocked()

if (mycontext == ...) {
notarizationBuilder.withImmutableDescription("...thedescription...");
}

if (mycontext == ...) {
notarizationBuilder.withUpdatableMetadata("...themetadata..."):
}
```
This results in no errors in the IDE or during compilation.

But at runtime, we'll get this error :

"Error: null pointer passed to rust "
(at the line : notarizationBuilder.withImmutableDescription(...))

### Expected behavior

No runtime errors

### Can the issue reliably be reproduced?

Yes

### Example repository

_No response_

### Steps to reproduce

-

### Language

WASM

### Language Version

-

### Version

v0.1.0

### Hardware specifications

-

### Additional info

_No response_