docs(style[private_path]): Reformat Python code block

why: ruff 0.16.0 formats Python code blocks inside Markdown by default,
so `ruff format . --check` now fails CI on the hand-aligned inline
comments in this doc.

what:
- Collapse comment padding to the two-space gap ruff format emits

https://astral.sh/blog/ruff-v0.16.0

Author: tony

docs/internals/api/private_path.md

@@ -18,8 +18,8 @@ internal logic.
 from vcspull._internal.private_path import PrivatePath
 
 home_repo = PrivatePath("~/code/vcspull")
-print(home_repo)          # -> ~/code/vcspull
-print(repr(home_repo))    # -> "PrivatePath('~/code/vcspull')"
+print(home_repo)  # -> ~/code/vcspull
+print(repr(home_repo))  # -> "PrivatePath('~/code/vcspull')"
 ```
 
 ## Usage guidelines