fix(tests): skip the actuation splice tests when ace-skills is absent

[contactacefleetdev]

Both tests assert that actuation changed the outbound bytes, which only happens when ace-skills is installed — it supplies the splice mechanics ShadowRunner.actuate imports lazily. That package is deliberately not a dependency of the sidecar, so CI's pip install -e .[test] never has it and actuate refuses by design, returning the original bytes.

Guard the two byte-changing tests with a skipif. Actuation's refusal paths and test_the_sidecar_still_works_with_no_lever_package_installed still run unconditionally, so the no-package behaviour stays covered.

Description

Summarize the changes made in this Pull Request and the problem being solved.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Verification

Describe the tests and checks performed to verify changes:

• pytest passes cleanly.
• python -m build and twine check dist/* pass.
• E2E test script scripts/e2e_test.py passes.

Checklist

• My code follows the code style of this project.
• I have updated documentation where necessary.
• I have updated CHANGELOG.md with my changes.