RSG (Ryan Specialty Group) recently announced a rename to Ryan Specialty (no
"Group"), but I'm not sure if the legal name has been changed yet or not, so
I'll wait on that.
Given that developers should be doing TDD and therefore running this target
frequently, this has the effect of providing immediate feedback when
formatting is needed and outputting a diff. Developers will then quickly
understand what changes need to be made to avoid future issues (and can run
`cargo fmt` to fix it), at which point they'll rarely ever encounter
formatting errors.
The original purpose was to ensure pipelines fail when the formatter has not
been run.