Merge bitcoin/bitcoin#29725: depends: build libqrencode with CMake

007ea322a6 depends: switch to building libqrencode with CMake (fanquake)
884330c0a5 guix: make cmake-minimal a global requirement (fanquake)

Pull request description:

  Switch to building libqrencode with CMake. Note that upstream (https://github.com/fukuchi/libqrencode) hasn't seen any activity for ~4 years, so the odds of getting anything upstream seems low, but I've made two minor changes to the source here, which I will PR in any case.

  From an initial look I couldn't find any significant difference between the Autotools and CMake produced libs. As part of this change we move cmake-minimal in Guix into the global package set.

ACKs for top commit:
  TheCharlatan:
    ACK 007ea322a6

Tree-SHA512: c784f790ddea958082c8ae96d3744bdf99331a8799765f9d44f00861b8e2cfcab1a88a3d64af5b10e51a8d5938d55eb6a3d271790b565e50492a39d00dc0e30f

depends/patches/qrencode/cmake_fixups.patch

@@ -0,0 +1,23 @@
+cmake: set minimum version to 3.5
+
+Correct some dev warning output.
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 773e037..a558145 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -1,4 +1,4 @@
+-cmake_minimum_required(VERSION 3.1.0)
++cmake_minimum_required(VERSION 3.5)
+ 
+ project(QRencode VERSION 4.1.1 LANGUAGES C)
+ 
+@@ -20,7 +20,7 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+ set(CMAKE_THREAD_PREFER_PTHREAD ON)
+ find_package(Threads)
+ find_package(PNG)
+-find_package(Iconv)
++find_package(ICONV)
+ 
+ if(CMAKE_USE_PTHREADS_INIT)
+     add_definitions(-DHAVE_LIBPTHREAD=1)