CI: Remove Qt installation on Msys2

.github/workflows/msys2-build.yml

@@ -39,12 +39,6 @@ jobs:
         install: git base-devel unzip p7zip mingw-w64-${{ matrix.arch }}-toolchain
         update: true
 
-    # Install Qt (required for shader nodes editor)
-    - name: Install Qt
-      uses: jurplel/install-qt-action@v2
-      with:
-        arch: win64_mingw81
-
     # Force xmake to a specific folder (for cache)
     - name: Set xmake env
       run: echo "XMAKE_GLOBALDIR=${{ runner.workspace }}/xmake-global" >> $GITHUB_ENV