The `|| true` is often done because people use `errexit` as part of "Bash strict mode"[1], which comes with so many caveats[2] that I usually avoid it. Claude, however, loves it.
Shortened commit SHAs are actually not supported by Actions; if you try, you get
"Unable to resolve action `actions/checkout@11bd719`, the provided ref `11bd719` is the shortened version of a commit SHA, which is not supported. Please use the full commit SHA `11bd71901bbe5b1630ceea73d27597364c9af683` instead."
In Ideas That Created the Future [1], a curated and edited set of influential computer science papers, the Leibniz contribution is "The True Method" [2], which I read more or less as "if we could formalize everything, we could use mathematical methods to find answers to all questions".
In the collection of papers, it's picked because of its ideas later formalized in Boolean logic, and logic programming in general.