Use single log call in graph examples

[Wumpf]

Makes the graph examples look a lil bit nicer and more compact.

Note that this is a very recent thing that we can do this in Rust 🥳

Also, embedds graph_directed in the examples (this has been done directly on the release branch already)

• full check passed in order to confirm the example output is still the same (tested this locally but who knows)

[Wumpf]

@rerun-bot full-check

[github-actions]

Started a full build: https://github.com/rerun-io/rerun/actions/runs/12392420135

[github-actions]

Web viewer built successfully. If applicable, you should also test it:

• I have tested the web viewer

Result	Commit	Link	Manifest
✅	9351b2a	https://rerun.io/viewer/pr/8527	+nightly +main

^{Note: This comment is updated whenever you push a commit.}