Fix session cleanup in WebSocket routes

Add missing `finally` blocks to ensure session removal in WebSocket routes after exceptions. This prevents potential memory leaks and ensures proper resource cleanup.

webserver/src/main/kotlin/space/mori/chzzk_bot/webserver/routes/WSSongListRoutes.kt

@@ -151,6 +151,7 @@ fun Routing.wsSongListRoutes() {
             }
         } catch (e: ClosedReceiveChannelException) {
             logger.error("Error in WebSocket: ${e.message}")
+        } finally {
             removeSession(uid)
         }
     }

webserver/src/main/kotlin/space/mori/chzzk_bot/webserver/routes/WSSongRoutes.kt

@@ -110,6 +110,7 @@ fun Routing.wsSongRoutes() {
             }
         } catch(e: ClosedReceiveChannelException) {
             logger.error("Error in WebSocket: ${e.message}")
+        } finally {
             removeSession(uid, this)
         }
     }

webserver/src/main/kotlin/space/mori/chzzk_bot/webserver/routes/WSTimerRoutes.kt

@@ -87,6 +87,7 @@ fun Routing.wsTimerRoutes() {
             }
         } catch(e: ClosedReceiveChannelException) {
             logger.error("Error in WebSocket: ${e.message}")
+        } finally {
             removeSession(uid, this)
         }
     }