Fix Qt component discovery by passing QT_ADDITIONAL_PACKAGES_PREFIX_PATH

Qt6Config.cmake hardcodes NO_DEFAULT_PATH when finding Qt components,
so CMAKE_PREFIX_PATH is completely ignored. It only searches its own
cmake dir (from qtbase) and QT_ADDITIONAL_PACKAGES_PREFIX_PATH.

Pass the same Homebrew prefix list as QT_ADDITIONAL_PACKAGES_PREFIX_PATH
so Qt's config machinery can locate qtdeclarative, qtsvg, qtmultimedia,
qtspeech, etc. Build verified locally on arm64.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: KorigamiK

build_mac.sh

@@ -57,7 +57,8 @@ rm -rf "$package_dir" "$build_dir/sioyek.app" "$build_dir/sioyek.dmg"
 
 "$CMAKE" -S . -B "$build_dir" \
   -DCMAKE_BUILD_TYPE=Release \
-  -DCMAKE_PREFIX_PATH="$cmake_prefix_path"
+  -DCMAKE_PREFIX_PATH="$cmake_prefix_path" \
+  -DQT_ADDITIONAL_PACKAGES_PREFIX_PATH="$cmake_prefix_path"
 
 "$CMAKE" --build "$build_dir" --parallel "$MAKE_PARALLEL"
 "$CMAKE" --install "$build_dir" --prefix "$package_dir"