remove unecessary allocation in RunContext

src/plugin.zig

@@ -99,12 +99,6 @@ pub const RunContext = struct {
             return ImageError.InstantiateFail;
         }
 
-        // we allocate []f32 with size 2 to account for stereo plugins, however
-        // we only use &in_buf[0] and &out_buf[0], and don't use the
-        // (supposedly) right side of neither input or output.
-        var in_buf = try allocator.alloc(f32, 2);
-        std.mem.secureZero(f32, in_buf);
-
         return RunContext{
             .buffers = try RunBuffers.init(allocator),
             .instance = instance.?,