remove JuliaCOn 2023 announcement (trixi-framework#1631)

README.md

@@ -17,16 +17,6 @@
   <img width="300px" src="https://trixi-framework.github.io/assets/logo.png">
 </p>
 
-***
-**Trixi.jl at JuliaCon 2023**<br/>
-At this year's JuliaCon, we will be present with an online contribution that involves Trixi.jl:
-
-* [Scaling Trixi.jl to more than 10,000 cores using MPI](https://pretalx.com/juliacon2023/talk/PC8PZ8/),
-  27th July 2023, 10:30–11:30 (US/Eastern), 32-G449 (Kiva)
-
-We are looking forward to seeing you there ♥️
-***
-
 **Trixi.jl** is a numerical simulation framework for hyperbolic conservation
 laws written in [Julia](https://julialang.org). A key objective for the
 framework is to be useful to both scientists and students. Therefore, next to