Don't compile the packet within basalt-server

[funnyboy-roks]

• Remove the compilation of the packet from basalt-server once Switch to Typst CLI bedrock#18 is complete.
• Add a new optional CLI argument which accepts the path to the packet PDF that should be served at /competition/packet.pdf
• Add endpoint at /competition that will give information about the competition (i.e., version, whether the web server is hosted, whether there is a packet download)