Merge bitcoin/bitcoin#30997: build: Switch to Qt 6

f00345727b doc: Update `dependencies.md` for Qt 6 (Hennadii Stepanov)
80b917991e build, msvc: Update `vcpkg.json` for Qt 6 (Hennadii Stepanov)
30dd1f1644 ci: Update for Qt 6 (Hennadii Stepanov)
629d292f4d test: Update sanitizer suppressions for Qt 6 (Hennadii Stepanov)
551e13abf8 guix: Adjust for Qt 6 (Hennadii Stepanov)
c3e9bd086c qt: Fix compiling for Windows (Hennadii Stepanov)
ab399c4db2 depends: Add `native_qt` package (Hennadii Stepanov)
248613eb3e depends: Factor out Qt modules' details (Hennadii Stepanov)
0268f52a4c depends: Introduce customizable `$(package)_patches_path` variables (Hennadii Stepanov)
5e794e6202 depends: Bump `qt` package up to 6.7.3 (Hennadii Stepanov)
6d4214925f cmake: Require Qt 6 to build GUI (Hennadii Stepanov)

Pull request description:

  The currently used Qt 5.15 is approaching [EOL](https://www.qt.io/blog/qt-5.15-extended-support-for-subscription-license-holders) and will reach it before the Bitcoin Core v30 release. The recent migration of the build system to CMake makes it possible to switch to Qt 6.

  This PR updates the OS runtime compatibility requirements for the Bitcoin Core GUI as follows:

  ### 1. Linux

  Starting with Qt 6.5.0, the `libxcb-cursor0` package is required to be installed at runtime.

  ### 2. Windows

  Cross-compiling does not support LTO. We have to re-add it in a follow-up.

  A new style plugin causes minor visual glitches, such as
  ![image](https://github.com/user-attachments/assets/e06f8685-aa79-49e7-9e61-4d54563f6d04)
  which will be fixed in follow-ups.

  ### 3. macOS

  `bitcoin-qt` now uses the [Metal](https://developer.apple.com/metal/) backend.

  ---

  **IMPORTANT.** Don't forget to install [Ninja](https://ninja-build.org/).

  ---

  For historical context, please refer to:
  - https://github.com/bitcoin/bitcoin/issues/20627
  - https://github.com/bitcoin/bitcoin/pull/24798

  ---

  UPD 2024-10-09. Qt 6.8 has been [released](https://www.qt.io/blog/qt-6.8-released), but it has some [drawbacks](https://github.com/bitcoin/bitcoin/pull/30997#issuecomment-2402990346) for us. As a result, this PR will stick to Qt 6.7.

  UPD 2025-03-18: [Standard support for Qt 5.15 will end after 26th of May 2025](https://www.qt.io/blog/extended-security-maintenance-for-qt-5.15-begins-may-2025)

ACKs for top commit:
  laanwj:
    re-ACK f00345727b
  hodlinator:
    re-ACK f00345727b

Tree-SHA512: 367f722e6c3ea4700b5395871c40b6df8c8062fdc822107090449ea4ae4ad2db75cc53a982a678f4c48ce8f9b2d43ed10e6d23b06165ab78713f161db712d895

.github/ISSUE_TEMPLATE/good_first_issue.yml

@@ -28,7 +28,7 @@ body:
     id: useful-skills
     attributes:
       label: Useful Skills
-      description: For example, “`std::thread`”, “Qt5 GUI and async GUI design” or “basic understanding of Bitcoin mining and the Bitcoin Core RPC interface”.
+      description: For example, “`std::thread`”, “Qt6 GUI and async GUI design” or “basic understanding of Bitcoin mining and the Bitcoin Core RPC interface”.
       value: |
         * Compiling Bitcoin Core from source
         * Running the C++ unit tests and the Python functional tests

.github/workflows/ci.yml

@@ -73,7 +73,7 @@ jobs:
           echo "TEST_BASE=$(git rev-list -n$((${{ env.MAX_COUNT }} + 1)) --reverse HEAD $EXCLUDE_MERGE_BASE_ANCESTORS | head -1)" >> "$GITHUB_ENV"
       - run: |
           sudo apt-get update
-          sudo apt-get install clang ccache build-essential cmake pkgconf python3-zmq libevent-dev libboost-dev libsqlite3-dev libdb++-dev systemtap-sdt-dev libzmq3-dev qtbase5-dev qttools5-dev qttools5-dev-tools qtwayland5 libqrencode-dev -y
+          sudo apt-get install clang ccache build-essential cmake ninja-build pkgconf python3-zmq libevent-dev libboost-dev libsqlite3-dev libdb++-dev systemtap-sdt-dev libzmq3-dev qt6-base-dev qt6-tools-dev qt6-l10n-tools libqrencode-dev -y
       - name: Compile and run tests
         run: |
           # Run tests on commits after the last merge commit and before the PR head commit
@@ -130,7 +130,7 @@ jobs:
         run: |
           # A workaround for "The `brew link` step did not complete successfully" error.
           brew install --quiet python@3 || brew link --overwrite python@3
-          brew install --quiet coreutils ninja pkgconf gnu-getopt ccache boost libevent zeromq qt@5 qrencode
+          brew install --quiet coreutils ninja pkgconf gnu-getopt ccache boost libevent zeromq qt@6 qrencode
 
       - name: Set Ccache directory
         run: echo "CCACHE_DIR=${RUNNER_TEMP}/ccache_dir" >> "$GITHUB_ENV"