[11.x] Removed null safe operator from whereNotMorphedTo

[mo7ameds7awky]

Issue Summary:
We identified an issue with the whereNotMorphedTo method in the Laravel framework. The issue stems from the use of the null safe operator <=>, which is not compatible with SQLite and PostgreSQL databases. This operator, while functioning correctly in MySQL, causes errors when used with other database systems.

The following error message was encountered during execution:

PDOException: SQLSTATE[HY000]: General error: 1 near ">": syntax error in vendor/laravel/framework/src/Illuminate/Database/Connection.php:407

Solution:
To ensure cross-database compatibility and to avoid unexpected errors, we propose removing or replacing the null safe operator <=> in the whereNotMorphedTo method. This change will enhance the framework's reliability across different database systems.

References:
This issue was discussed and partially addressed in a previous PR: #42878, which initially proposed the use of the null safe operator.

[taylorotwell]

Seems like just removing code could break other use cases?

[taylorotwell]

This would just reintroduce another bug?

[mo7ameds7awky]

I believe there is no bug in the current implementation of the whereNotMorphedTo method.

The whereNotMorphedTo method's first parameter does not receive null models. The previous discussion about null values #42264 (comment) was a hypothetical scenario that does not occur in practice.

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!

[chrisreedio]

@mo7ameds7awky I've run into this issue on Postgres. Since this PR was closed, did you ever come up with a work around?

[mo7ameds7awky]

@chrisreedio Yes, there are two workarounds here, first you can revert your condition for example:
->whereNot(fn (Builder $query) => $query->whereMorphedTo('relation-name', $model))
, second you can convert this one function into two checks for example:
->where('model_type', 'type')->where('model_id', 'id')