Force Qt deprecation cutoff for all targets

Author: vectorrilke

.github/workflows/ci_windows_arm64_native.yaml

@@ -208,6 +208,9 @@ jobs:
           $commonConfig = $commonConfig -replace "QT_DISABLE_DEPRECATED_UP_TO=0x060500", "QT_DISABLE_DEPRECATED_UP_TO=0x060A00"
           Set-Content $commonConfigPath -Value $commonConfig
 
+          # Ensure the deprecation cutoff applies to every target, including qbt_app.
+          $env:CXXFLAGS = (($env:CXXFLAGS + " /DQT_DISABLE_DEPRECATED_UP_TO=0x060A00").Trim())
+
           cmake `
             -B build `
             -G Ninja `