[flake8-bugbear ] Add fix safety section (B006)

[Kalmaegi]

Summary

This PR add the fix safety section for rule B006 in mutable_argument_default.rs for #15584

When applying this rule for fixes, certain changes may alter the original logical behavior. For example:

before:

def cache(x, storage=[]):
    storage.append(x)
    return storage

print(cache(1))  # [1]
print(cache(2))  # [1, 2]

after:

def cache(x, storage=[]):
    storage.append(x)
    return storage

print(cache(1))  # [1]
print(cache(2))  # [2]

[github-actions]

ruff-ecosystem results

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✅ ecosystem check detected no linter changes.

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[ntBre]

Thank you!