fix: add ssz feature back for alloy-primitives to fix test compiling

[KolbyML]

What was wrong?

the tests I am trying to run locally are all failing, because we removed the ssz feature from alloy-primitives in the PR updating Cargo to properly use workplace

so I got thousands of error's stating can't derive ssz for B256, ... 5 billion other errors etc. I was running tests in block_body.rs

depends

How was it fixed?

by adding the feature back which was removed

[morph-dev]

I would even consider enabling this feature in the [workspace.dependencies] in root Cargo.toml.

[morph-dev]

Now you can remove it from trin-validation/Cargo.toml