dag: fix dot file rendering order.

[tirkarthi]

• ❗ I have followed the Contributing to DVC checklist.

• 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.

Thank you for the contribution - we'll try to review it as soon as possible. 🙏

Closes #7676

[tirkarthi]

• Before PR

• After PR

The PR makes the output consistent with mermaid option output as seen below :

[daavoo]

Fix test

[daavoo]

It is not strictly in the scope of the P.R. but would be a good occasion to add a --dot example output in https://dvc.org/doc/command-reference/dag

$ dvc dag --dot
strict digraph  {
prepare;
featurize;
train;
evaluate;
"data/data.xml.dvc";
prepare -> featurize;
featurize -> train;
featurize -> evaluate;
train -> evaluate;
"data/data.xml.dvc" -> prepare;
}

[tirkarthi]

@daavoo Thanks, the page also seems to be missing options like mermaid and markdown. I will update the docs.

  --mermaid        Print DAG with mermaid format.
  --md, --show-md  Print DAG with mermaid format wrapped in Markdown
                   block.

[daavoo]

@daavoo Thanks, the page also seems to be missing options like mermaid and markdown. I will update the docs.

  --mermaid        Print DAG with mermaid format.
  --md, --show-md  Print DAG with mermaid format wrapped in Markdown
                   block.

For mermaid/markdown there is an open P.R. (iterative/dvc.org#3454) but for the rest would be great 🙌

[tirkarthi]

Windows test failure seems unrelated to the PR. It fails even after rebase with master and rerun.

[efiop]

Thank you, @tirkarthi ! 🙏

[tirkarthi]

Thanks @Ruslan and @daavoo