[5.1] Fix timestamps on update

[acasar]

This fixes #10028 where timestamps are updated even if ['timestamps' => false] is passed to the save() method.

The easiest solution would be to simply pass the $options array to the update method on the Builder but since that would be a breaking change (someone may be extending the Builder) I added a new flag $shouldUpdateTimestamps that is set to false if timestamps were disabled.

[JosephSilber]

Since we're not updating timestamps if $timestamps is set to false on the model, how about inverting that property and calling it $skipUpdatingTimestamp?

[taylorotwell]

To me it feels really, really silly to have this new property that we are setting to true / false at random times. I don't know, something about this all feels really hacky.

[acasar]

Yeah it is a bit hacky but I don't have any other idea right now on how to fix it without breaking BC. Let me look at this a bit more tomorrow. Maybe I can find some better alternative.

[taylorotwell]

I mean just off the top of my head. What if something in a model updated event updates a different field on the model and does want the timestamps updated?

[vlakoff]

As a reminder, DatabaseEloquentModelTest::testTimestampsAreNotUpdatedWithTimestampsFalseSaveOption isn't actually testing the functionality.

That's a good example of what could happen when a test has to hook mocks into the implementation of what is being tested.

[acasar]

@taylorotwell I found a better solution. I added a method withoutTimestamps() to the Builder which fixes the issue. This solution has additional benefits - it can be used directly when updating multiple records:

User::withoutTimestamps()->update(['active' => 1]);

@vlakoff Yeah mocking Eloquent is never a good idea. That's why I added a proper integration test for this issue.

[taylorotwell]

I don't even really want to support this at all. If you want to update a DB record without updating the timestamps use the query builder. This will lead to all kinds of more code to support weird edge cases where I want to not update the timestamps on the main model but I want to touch or not touch the parent models, etc. I don't even want to go down this rabbit hole.