fix: correct RFC 3986 section reference in path_template docstring

[aryanmotgi]

What

The path_template docstring in src/openai/_utils/_path.py references "RFC 3986 §3.3" when describing the safe character set used for the query portion. The correct section for the query component is §3.4 — §3.3 is the Path component.

Evidence

src/openai/_utils/_path.py:92 (before):

Placeholders in the query portion are percent-encoded where the `query` set from
RFC 3986 §3.3 is considered safe except for = and & characters.

For comparison, the helper that actually does the query quoting documents itself correctly (src/openai/_utils/_path.py:32-33):

Considers &, = and characters not in `query` set from RFC 3986 §3.4 to be unsafe.
https://datatracker.ietf.org/doc/html/rfc3986#section-3.4

RFC 3986 reference:

• §3.3 — Path (https://datatracker.ietf.org/doc/html/rfc3986#section-3.3)
• §3.4 — Query (https://datatracker.ietf.org/doc/html/rfc3986#section-3.4)

Fix

One-character docstring correction: §3.3 → §3.4. No behavior change.