Bump platforms crate to 3.5.0

Summary:
Bumps the `platforms` crate from rustsec to 3.5.0. The version currently vendored in (3.0.2, Nov 2022) does not have rustsec/rustsec@a4d7fc5 (Feb 2023) which added target_os "aix". RUSTSEC-2025-0001 for `gix-worktree-state` specifies a `target_os` of `aix`, so `vendor` doesn't work right now (P1716441030).

(I created this diff with `--audit-sec` removed on this line: https://www.internalfb.com/code/fbsource/fbcode/common/rust/tools/reindeer/script-common.sh?lines=127)

Reviewed By: zertosh

Differential Revision: D68474729

fbshipit-source-id: bc09ba098de405f73e0798360c19f23932fd210b