Made compilation work with unity builds

src/libs/services/scanner/impl/steps/ScanStepAssociateExternalLyrics.cpp

@@ -32,9 +32,6 @@ namespace lms::scanner
 {
     namespace
     {
-        constexpr std::size_t readBatchSize{ 100 };
-        constexpr std::size_t writeBatchSize{ 20 };
-
         struct TrackLyricsAssociation
         {
             db::TrackLyricsId trackLyricsId;
@@ -83,6 +80,8 @@ namespace lms::scanner
 
         bool fetchNextTrackLyricsToUpdate(SearchTrackLyricsContext& searchContext, TrackLyricsAssociationContainer& trackLyricsAssociations)
         {
+            constexpr std::size_t readBatchSize{ 100 };
+
             const db::TrackLyricsId trackLyricsId{ searchContext.lastRetrievedTrackLyricsId };
 
             {
@@ -125,6 +124,8 @@ namespace lms::scanner
 
         void updateTrackLyrics(db::Session& session, TrackLyricsAssociationContainer& lyricsAssociations)
         {
+            constexpr std::size_t writeBatchSize{ 20 };
+
             while (!lyricsAssociations.empty())
             {
                 auto transaction{ session.createWriteTransaction() };