download: use new etag cache file and delete the old one, this removes all the old themezer entries.

sphaira/source/app.cpp

@@ -1495,9 +1495,10 @@ App::App(const char* argv0) {
         }
 
         {
-            // delete old themezer cache as themezer does not exit anymore.
-            SCOPED_TIMESTAMP("themezer cache delete");
-            m_fs->DeleteDirectoryRecursively("/switch/sphaira/cache/themezer");
+            // delete old cached folders/files on startup.
+            SCOPED_TIMESTAMP("old cache delete");
+            m_fs->DeleteDirectoryRecursively("/switch/sphaira/cache/themezer"); // themezer icon/json cache.
+            m_fs->DeleteFile("/switch/sphaira/cache/cache.json"); // old etag cache.
         }
 
         if (log_is_init()) {

sphaira/source/download.cpp

@@ -247,7 +247,7 @@ private:
         }
     }
 
-    static constexpr inline fs::FsPath JSON_PATH{"/switch/sphaira/cache/cache.json"};
+    static constexpr inline fs::FsPath JSON_PATH{"/switch/sphaira/cache/etag_v2.json"};
     static constexpr inline const char* ETAG_STR{"etag"};
     static constexpr inline const char* LAST_MODIFIED_STR{"last-modified"};