doc: Document current boost dependency as 1.71.0

This was forgotten in #19764.

Author: laanwj

doc/dependencies.md

@@ -6,7 +6,7 @@ These are the dependencies currently used by Bitcoin Core. You can find instruct
 | Dependency | Version used | Minimum required | CVEs | Shared | [Bundled Qt library](https://doc.qt.io/qt-5/configure-options.html#third-party-libraries) |
 | --- | --- | --- | --- | --- | --- |
 | Berkeley DB | [4.8.30](https://www.oracle.com/technetwork/database/database-technologies/berkeleydb/downloads/index.html) | 4.8.x | No |  |  |
-| Boost | [1.70.0](https://www.boost.org/users/download/) | [1.58.0](https://github.com/bitcoin/bitcoin/pull/19667) | No |  |  |
+| Boost | [1.71.0](https://www.boost.org/users/download/) | [1.58.0](https://github.com/bitcoin/bitcoin/pull/19667) | No |  |  |
 | Clang |  | [5.0+](https://releases.llvm.org/download.html) (C++17 support) |  |  |  |
 | Expat | [2.2.7](https://libexpat.github.io/) |  | No | Yes |  |
 | fontconfig | [2.12.1](https://www.freedesktop.org/software/fontconfig/release/) |  | No | Yes |  |