fix(sozo): handle edge case when base_class_hash is FieldElement::ZERO

[itzlambda]

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 16.66667% with 10 lines in your changes are missing coverage. Please review.

Project coverage is 69.71%. Comparing base (628542f) to head (01bf09d). Report is 5 commits behind head on main.

Files	Patch %	Lines
crates/sozo/ops/src/migration/migrate.rs	22.22%	7 Missing :warning:
crates/dojo-world/src/manifest/mod.rs	0.00%	3 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1978      +/-   ##
==========================================
- Coverage   69.80%   69.71%   -0.09%     
==========================================
  Files         313      314       +1     
  Lines       35527    35639     +112     
==========================================
+ Hits        24799    24847      +48     
- Misses      10728    10792      +64     

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