Merge bitcoin/bitcoin#32211: doc: Amend Qt 6 dependency packages for Ubuntu

2e751f5 doc: Amend Qt 6 dependency packages for Ubuntu (Hennadii Stepanov)

Pull request description:

  On older systems, such as Ubuntu 22.04, `qt6-tools-dev-tools` and `libgl-dev` are not treated as dependencies of `qt6-tools-dev` and `qt6-base-dev`, respectively. This PR explicitly lists them in the installation documentation.

  Fixes bitcoin/bitcoin#32210.

ACKs for top commit:
  maflcko:
    lgtm ACK 2e751f5
  laanwj:
    Code review ACK 2e751f5

Tree-SHA512: a6997c74c83789cb5fe5b97a719b8ff6e2180d5f6ae5502ccccfce3a22394d25eef05204ecda0a6deb368de77975e2a1da89b5749eff01a979f2f60843efebff

Author: hebasto

doc/build-unix.md

@@ -73,7 +73,7 @@ GUI dependencies:
 Bitcoin Core includes a GUI built with the cross-platform Qt Framework. To compile the GUI, we need to install
 the necessary parts of Qt, the libqrencode and pass `-DBUILD_GUI=ON`. Skip if you don't intend to use the GUI.
 
-    sudo apt-get install qt6-base-dev qt6-tools-dev qt6-l10n-tools
+    sudo apt-get install qt6-base-dev qt6-tools-dev qt6-l10n-tools qt6-tools-dev-tools libgl-dev
 
 For Qt 6.5 and later, the `libxcb-cursor0` package must be installed at runtime.