Merge bitcoin#29066: Bump minimum required Boost version due to migration to C++20

49a9091 build: Bump minimum required Boost to 1.73.0 to support C++20 (Hennadii Stepanov)

Pull request description:

  Boost versions <1.73 have C++20-specific bugs that were fixed in the following commits:
  - boostorg/signals2@15fcf21
  - boostorg/test@495c095

  I tested [`libboost1.71-dev`](https://packages.ubuntu.com/focal/libboost1.71-dev) in Ubuntu 20.04 and Boost 1.71, 1.72, 1.73 in our depends build system.

  Closes bitcoin#29063.

ACKs for top commit:
  fanquake:
    ACK 49a9091

Tree-SHA512: b8ebc08af85abfa3fda70961bd1136ee9e5149dd76a3f901e43acba624d231971873cba5cbf30837f9e5ab58790b8330f241a76cb76d8cf5dce5ad0cca33fba8

Author: fanquake

configure.ac

@@ -1461,7 +1461,7 @@ fi
 if test x$use_boost = xyes; then
 
 dnl Check for Boost headers
-AX_BOOST_BASE([1.64.0],[],[AC_MSG_ERROR([Boost is not available!])])
+AX_BOOST_BASE([1.73.0],[],[AC_MSG_ERROR([Boost is not available!])])
 if test x$want_boost = xno; then
     AC_MSG_ERROR([[only libdashconsensus can be built without boost]])
 fi

doc/dependencies.md

@@ -6,7 +6,7 @@ These are the dependencies currently used by Dash Core. You can find instruction
 | 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 | [1.81.0](https://www.boost.org/users/download/) | [1.64.0](https://github.com/bitcoin/bitcoin/pull/22320) | No |  |  |
+| Boost | [1.81.0](https://www.boost.org/users/download/) | [1.73.0](https://github.com/bitcoin/bitcoin/pull/29066) | No |  |  |
 | Clang<sup>[ \* ](#note1)</sup> |  | [5.0+](https://releases.llvm.org/download.html) (C++17 support) |  |  |  |
 | fontconfig | [2.12.1](https://www.freedesktop.org/software/fontconfig/release/) |  | No | Yes |  |
 | FreeType | [2.11.0](https://download.savannah.gnu.org/releases/freetype) |  | No |  | [Yes](https://github.com/dashpay/dash/blob/develop/depends/packages/qt.mk) (Android only) |