[Linux/Ubuntu] Stock instructions need updating for .NET 8

[MartinHowe426]

On a fresh install of Linux Mint, followed the instructions in the Readme. All is well until I try to run the build script; then the error "./Scripts/build.sh: line 3: dotnet: command not found" occurs. This can be fixed by installing dotnet7 from the apt package manager; but that fails with a compiler error on the new collection expressions feature. Building with .NET 8 and its SDK fixes the problem and it doesn't seem to need dotnet8 be installed explicitly.

So please can the build instructions for Ubuntu be updated accordingly?

sudo apt install dotnet-sdk-8.0 libfluidsynth-dev libopenal-dev