Fix WebAssembly (WASM) support for Qt 6.7+

[Kidev]

Fix WebAssembly (WASM) support for Qt 6.7+

Description

Adds support for downloading and installing Qt WASM packages for Qt versions 6.7.0 and above, while remaining backward compatible. Starting from Qt 6.7.0, the Qt WebAssembly (WASM) packages have been moved to a new repository structure at https://download.qt.io/online/qtsdkrepository/all_os/wasm/.

This PR updates the path handling to properly support:

• Qt 6.7.x: qt6_67x_wasm_singlethread and qt6_67x_wasm_multithread
• Qt 6.8.x: qt6_680/qt6_680_wasm_singlethread and qt6_680/qt6_680_wasm_multithread

Changes

• Added 'wasm' target to all_os supported targets
• Updated WASM path construction to handle both Qt 6.7.x and 6.8.x structures
• Updated version detection to properly handle Qt 6.7+ WASM packages
• Added debug logs for easier troubleshooting of the Updates.xml URL generation process

Example Usage

aqt install-qt linux desktop 6.7.3 wasm_singlethread --autodesktop --modules qtquick3d qtquicktimeline qtshadertools

About qt-install-action

It works on a ubuntu-24.04 runner at least, I tested it on a personal project: the wasm arch is downloaded and behave as expected. You just need to specify (at least until the fixes are pushed to master) aqtsource as git+https://github.com/Kidev/aqtinstall.git:

      - name: Install Qt
        uses: jurplel/[email protected]
        with:
          version: '6.7.3'
          host: 'linux'
          target: 'desktop'
          arch: 'wasm_singlethread'
          modules: 'qtquick3d qtquicktimeline qtshadertools'
          extra: '--autodesktop'
          aqtsource: 'git+https://github.com/Kidev/aqtinstall.git'