Use 'new' expression in places where the type is evident for content (#2590)

* Content.Client

* Content.Benchmarks

* Content.IntegrationTests

* Content.Server

* Content.Server.Database

* Content.Shared

* Content.Tests

* Merge fixes

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Content.Client/GameObjects/Components/Instruments/InstrumentComponent.cs

@@ -50,7 +50,7 @@ namespace Content.Client.GameObjects.Components.Instruments
         ///     A queue of MidiEvents to be sent to the server.
         /// </summary>
         [ViewVariables]
-        private readonly List<MidiEvent> _midiEventBuffer = new List<MidiEvent>();
+        private readonly List<MidiEvent> _midiEventBuffer = new();
 
         /// <summary>
         ///     Whether a midi song will loop or not.