Silence bytecode compile failures during install

[itscloud0]

Summary

• silence bytecode compilation failures by using compileall's fully quiet mode
• keep installer behavior aligned with pip by still ignoring compile failures instead of aborting installation
• add a regression test that locks in silent handling for failed bytecode compilation

Closes #311

Problem

installer currently ignores bytecode compilation failures, but it still emits *** Error compiling ... messages to stderr. That is noisy for wheels that intentionally contain Python files targeting newer syntax, and it does not match pip's behavior noted in the issue discussion.

Testing

• uv run --python 3.10 --with pytest pytest tests/test_main.py -q
• uv run --python 3.10 --with pytest --with pytest-cov --with pytest-xdist pytest -q
• uv run --python 3.10 --with ruff ruff check src/installer/destinations.py tests/test_main.py
• uv run --python 3.10 --with ruff ruff format --check src/installer/destinations.py tests/test_main.py

Notes

• I did not change install success/failure semantics; this only removes the noisy stderr output while preserving the existing ignore-and-continue behavior discussed on the issue.