Fix: Add null check for Select field options in fields_layout

[pu-raihan]

Changes:

• Added a null check (and field.options) in the condition to handle cases where options are empty or undefined for "Select" type fields.

Why is this needed?

When I added a custom field of type Select without options, then code attempted to split field.options without checking if it existed, which could result in errors when field.options is None or an empty string which resulted in error and not loading all the fields after that field. By adding this check, we ensure that the code only attempts to split the options when field.options has a value.

Code Changes:

if field.fieldtype == "Select" and field.options:
    field.options = field.options.split("\n")

### Reproduce Issue:
Try creating a select field without options and then add it in sections field layout. then if you try to edit the layout it will cause the error and some of the fields (fields shown after the new field) will not show up