chore: use gapic-generator-python 0.65.1 (#377)

- [ ] Regenerate this pull request now.

PiperOrigin-RevId: 441524537

Source-Link: googleapis/googleapis@2a27391

Source-Link: googleapis/googleapis-gen@ab6756a
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiYWI2NzU2YTQ4Yzg5YjViY2I5ZmI3MzQ0M2NiOGU1NWQ1NzRmNDY0MyJ9

docs: fix type in docstring for map fields

Author: gcf-owl-bot[bot]