R CMD check found ERRORs

Test failures

Process completed with exit code 1.

Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: actions/checkout@v3. For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.

fn_simulate_sparse_mixed_model_data.Rd:21: unknown macro '\times'

fn_simulate_sparse_mixed_model_data.Rd:21: unknown macro '\over'

fn_simulate_sparse_mixed_model_data.Rd:21: unknown macro '\times'