respect indent_by when curly brace is added

[lorenzwalthert]

Closes #909.

[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 59b5304 is merged into main:

•   :ballot_box_with_check:cache_applying: 31.4ms -> 31.9ms [-1.7%, +5.24%]
•   :ballot_box_with_check:cache_recording: 1.5s -> 1.51s [-0.52%, +2.65%]
•   :ballot_box_with_check:without_cache: 4.05s -> 4.07s [-1.22%, +2.24%]

Further explanation regarding interpretation and methodology can be found in the documentation.