arrow

MINOR: [Python][Docs] Fix typo (#34362)

### Rationale for this change

Fix the typo found in #34340 which copied from this file.

### What changes are included in this PR?

Minor typo fixes.

### Are these changes tested?

No. Minor documentation changes only.

### Are there any user-facing changes?

No.

Authored-by: SHIMA Tatsuya <ts1s1andn@gmail.com>
Signed-off-by: Alenka Frim <frim.alenka@gmail.com>