Create new track for "rustup"

Hello,

Please create a new “RVA20” track for the “rustup” snap so we can provide RISC-V RVA20 support on core24 in parallel with RISC-V RVA23 support on core26.

Rustup snap: Install rustup - The Rust Language installer on Linux | Snap Store

Related GitHub issue: Can't install rustup on RISC-V RVA20 (Ubuntu 24.04): snap "core26" assumes isa-riscv64-rva23 · Issue #11 · canonical/rustup-snap · GitHub

Track RVA20 has been created.

Thank you, Melvin! :smiley: