fix typo in DFS iterator description

Signed-off-by: Philip Conrad <conradp@chariot-chaser.net>
try to fix busted deps on Alpine
bump OpenBSD from 6.9 to 7.1
Revert "implement thread safety"

This seems to have deadlocks the tests don't catch.

This reverts commit da42499182d55cd27bee717cd78ffe930a357efd.
implement thread safety
implement compatible for use with gonum/graph
fix return type for Must{Source,Sink}
add ForeachNode and ForeachEdge
add test cases for ReplaceData
add ReplaceData to node and edge
add benchmarks for BFS and DFS
implement BFS traversal
add edge iteration for nodes
add support for node and edge deletion