bump tracing-attributes to a pre-release

Summary:
I bumped tracing-attributes to a prerelease to address an issue where `String` was recorded using the `Debug` visitor.

Reported in https://fb.workplace.com/groups/rust.language/posts/26931113416510585.

Reviewed By: capickett

Differential Revision: D64617960

fbshipit-source-id: 3ff793bcecda58856e657911a4df9692c38ca092

Cargo.toml

@@ -24,6 +24,7 @@ plexi-core = { git = "https://github.com/haochenuw/plexi", rev = "a0326d9802a594
 pyo3-build-config = { package = "pyo3-build-config", version = "0.21.2", git = "https://github.com/fbsource/pyo3", rev = "ff94a09031cc29d88d57ae3c846e5b871497aeb9" }
 quickcheck = { git = "https://github.com/jakoschiko/quickcheck", rev = "6ecdf5bb4b0132ce66670b4d46453aa022ea892c" }
 riscv = { git = "https://github.com/rust-embedded/riscv.git", rev = "28e9b02d45827055188be0dbd1f800ba64bc75e6" }
+tracing-attributes = { git = "https://github.com/tokio-rs/tracing.git", rev = "70a867877d5232b686d5fd70bbb4cbf37f4b38c6" }
 
 [workspace]
 members = [