v4.13.1

• fix(perf): back out commit 808b951 which causes a severe performance regression in Dijkstra algorithm
• style: use usize::div_ceil()
• feat(gitignore): ignore flame graph files
• docs: cleanup some first line
• chore(deps): update rust crate itertools to 0.14.0
• fix(clippy): put test module last in file
• feat: accept &(usize, usize) as Matrix index
• fix(style): use a less convoluted test