refactor(data/real/irrational): review (#2304)
* refactor(data/real/irrational): review
* Update src/data/real/irrational.lean
* Update src/data/real/irrational.lean
* Apply suggestions from code review
Co-authored-by: sgouezel <sebastien.gouezel@univ-rennes1.fr>
Co-authored-by: Scott Morrison <scott@tqft.net>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
