Bump petgraph from 0.6.4 to 0.6.5

Bumps [petgraph](https://github.com/petgraph/petgraph) from 0.6.4 to 0.6.5.
- [Changelog](https://github.com/petgraph/petgraph/blob/master/RELEASES.rst)
- [Commits](https://github.com/petgraph/petgraph/compare/petgraph@v0.6.4...petgraph@v0.6.5)

---
updated-dependencies:
- dependency-name: petgraph
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -36,7 +36,7 @@ crate-type = ["cdylib", "rlib"]
 itertools = "0.12.1"
 lazy_static = "1.4.0"
 ndarray = "0.15.6"
-petgraph = {version = "0.6.4", default-features = false, features = ["stable_graph"]}
+petgraph = {version = "0.6.5", default-features = false, features = ["stable_graph"]}
 regex = "1.10.4"
 unic-char-range = "0.9.0"
 unic-ucd-category = "0.9.0"