PERF: only apply nanops rowwise optimization for narrow arrows
See the timings in https://github.com/pandas-dev/pandas/pull/43311#issuecomment-974891737

(this is a regression compared to previous release mostly when using ArrayManager (and thus doesn't need a whatsnew) and is covered by the FrameOps benchmarks)
Verified that the remaining failure is only an unrelated ResourceWarning thanks @jorisvandenbossche  LGTM.  merits an asv? > LGTM. merits an asv?

It gave a huge slowdown in the current ASVs when running with ArrayManager, so in that way it's already captured. 

We could add one for wide dataframes as well, ~but you already need an extreme shape (like 10, 1000), so I personally don't find that a very interesting one to add.~ Misremembered this, so you actually already see a speed-up with something like (1000, 10). > so in that way it's already captured

id be more comfortable with one that always runs