Use package-relative imports in buildcompiler

[Gonza10V]

Motivation

• Ensure internal module imports resolve correctly when the package is installed by switching buildcompiler.py to package-relative imports.

Description

• Update src/buildcompiler/buildcompiler.py to use from .abstract_translator import translate_abstract_to_plasmids, from .sbol2build import golden_gate_assembly_plan, and from .robotutils import assembly_plan_RDF_to_JSON, run_opentrons_script_with_json_to_zip so internal imports are package-scoped.

Testing

• Ran python -m pytest, which executed the test suite but ended with 4 failed, 5 passed, 3 errors due to network/proxy failures contacting external SBOL services; ran ruff check ., which reported many existing lint issues across notebooks and scripts (these are preexisting and not caused by this change).

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Codex Task