Remove unused runtime dependencies (numba, llvmlite, cmaes) and demote cyclopts #12

Problem

Three packages are declared as hard runtime dependencies but are imported
nowhere in src/:

Verify with:

grep -rnE "import (numba|cmaes|cyclopts|llvmlite)|from (numba|cmaes|cyclopts|llvmlite)" src/
# no matches

The cost is paid by every downstream user: a much larger install, a slower
resolve, a bigger vulnerability surface, and — worst of all — numba pins the
compatible NumPy range, so it can block users from upgrading NumPy for reasons
that have nothing to do with this library.

Proposed fix

• Remove numba, llvmlite and cmaes from [project.dependencies] entirely.
• Move cyclopts out of the runtime dependencies into a bench dependency
  group, since only the benchmark scripts use it.
• Regenerate uv.lock.

After this change the runtime dependency set should be just: numpy,
opt_einsum, quimb (and structlog until #1 lands, which removes it too).

Acceptance criteria

• numba, llvmlite, cmaes removed from [project.dependencies].
• cyclopts available to the benchmarks via a dependency group, not at runtime.
• uv.lock regenerated.
• Test suite still passes and the benchmark script still runs.