Replace build() with build_in_name_scope() for some TF tests

[Rocketknight1]

Should have included this in the TF build() PR but I missed it until now - some of the TF tests should use build_in_name_scope() to ensure layer names aren't changed by that PR!

This fix is just for our tests - users shouldn't be affected by the build() PR unless they're manually calling build() on models and then trying to crossload weights into them.

[HuggingFaceDocBuilderDev]

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[amyeroberts]

Thanks for fixing!

More generally for this case:

This fix is just for our tests - users shouldn't be affected by the build() PR unless they're manually calling build() on models and then trying to crossload weights into them.

Is this something which would fail silently for our users? I'd be surprised if many people were trying to do this, but would be good to at least have an exception thrown somewhere if they do

[Rocketknight1]

@amyeroberts It's hard to say - it would depend exactly on how they were loading the weights. What has changed with this PR is that if you initialize a model via from_config and then explicitly call its build() method, you'll get slightly different weight names for it than you would have before. For every other case (e.g. initialize with from_pretrained() or implicitly call build() via calling the model), there should be no difference.

I think for users to notice an issue they would need to:

1. Load a model with from_config
2. Explicitly build it with build()
3. Have their own weight-loading script that they use to load weights by name into their model after 2)

I think it's pretty unlikely that anyone is doing that, and even if so, they can fix it by using build_in_name_scope() instead.