docs: rust: quick-start: remove GDB/Binutils mention

The versions provided nowadays by even a distribution like Debian Stable
(and Debian Old Stable) are newer than those mentioned [1].

Thus remove the workaround.

Note that the minimum binutils version in the kernel is still 2.30, so
one could argue part of the note is still relevant, but it is unlikely
a kernel developer using such an old binutils is enabling Rust on a
modern kernel, especially when using distribution toolchains, e.g. the
Rust minimum version is not satisfied by Debian Old Stable.

So we are at the point where keeping the docs short and relevant for
essentially everyone is probably the better trade-off.

Link: https://packages.debian.org/search?suite=all&searchon=names&keywords=binutils [1]
Link: https://lore.kernel.org/all/CANiq72mCpc9=2TN_zC4NeDMpFQtPXAFvyiP+gRApg2vzspPWmw@mail.gmail.com/
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-29-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Documentation/rust/quick-start.rst

@@ -352,12 +352,3 @@ Hacking
 To dive deeper, take a look at the source code of the samples
 at ``samples/rust/``, the Rust support code under ``rust/`` and
 the ``Rust hacking`` menu under ``Kernel hacking``.
-
-If GDB/Binutils is used and Rust symbols are not getting demangled, the reason
-is the toolchain does not support Rust's new v0 mangling scheme yet.
-There are a few ways out:
-
-- Install a newer release (GDB >= 10.2, Binutils >= 2.36).
-
-- Some versions of GDB (e.g. vanilla GDB 10.1) are able to use
-  the pre-demangled names embedded in the debug info (``CONFIG_DEBUG_INFO``).