`riscv64a23-unknown-linux-gnu` promotion not reflected in docs

[jpalus]

Location (URL)

https://doc.rust-lang.org/rustc/platform-support.html

Summary

According to rust 1.93.0 release notes riscv64a23-unknown-linux-gnu platform got promoted to Tier 2 (without host tools) in: #148435. However platform support page, linked in same release notes, still lists the target as Tier 3. I believe #148435 missed update in:
https://github.com/rust-lang/rust/blob/main/src/doc/rustc/src/platform-support.md

cc: @ZhongyaoChen

[ozankenangungor]

I can take this and update platform-support.md accordingly.

@rustbot claim

[ZhongyaoChen]

@jpalus @ozankenangungor Wow thanks!! Appreciate you pointing it out and fixing it. ^_^