Context

Regressions in etc/install-libmongocrypt.sh would only surface as cascading failures across many Evergreen CSFLE/QE tasks, making diagnosis costly.

Definition of done

• Create an evergreen matrix for "Script Check"
• A new test suite at internal/test/scriptcheck
• Taskfile target to run internal/test/scriptcheck that plugs into "Script Check"

Pitfalls

• The implementer needs to make sure the test is a smoke test, not just that the script runs with exit 0.
• Can't test windows branch of script.