chore(category_theory/triangulated/rotate): optimizing some proofs (#12031)
chore(category_theory/triangulated/rotate): optimizing some proofs (#12031)

Removes some non-terminal `simp`s; replaces some `simp`s by `simp only [...]` and `rw`.

Compilation time dropped from 1m40s to 1m05s on my machine.





leanprover-community/mathlib,leanprover-community/mathlib