docs: rust: quick-start: add Debian 13 (Trixie)

Debian 13 (released 2025-08-09) packages Rust 1.85.0 [1], which is recent
enough to build Linux.

Thus document it.

In fact, we are planning to propose that the minimum supported Rust
version in Linux follows Debian Stable releases, with Debian 13 being
the first one we upgrade to, i.e. Rust 1.85.

Link: https://www.debian.org/News/2025/20250809 [1]
Link: https://patch.msgid.link/20251012224645.1148411-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

Documentation/rust/quick-start.rst

@@ -39,8 +39,8 @@ of the box, e.g.::
 Debian
 ******
 
-Debian Testing and Debian Unstable (Sid), outside of the freeze period, provide
-recent Rust releases and thus they should generally work out of the box, e.g.::
+Debian 13 (Trixie), as well as Testing and Debian Unstable (Sid) provide recent
+Rust releases and thus they should generally work out of the box, e.g.::
 
 	apt install rustc rust-src bindgen rustfmt rust-clippy