Rollup merge of #129767 - nnethercote:rm-extern-crate-tracing-4, r=jieyouxu

Remove `#[macro_use] extern crate tracing`, round 4

Because explicit importing of macros via use items is nicer (more standard and readable) than implicit importing via #[macro_use]. Continuing the work from #124511, #124914, and #125434. After this PR no `rustc_*` crates use `#[macro_use] extern crate tracing` except for `rustc_codegen_gcc` which is a special case and I will do separately.

r? ```@jieyouxu```

compiler/rustc_infer/src/traits/project.rs

@@ -4,6 +4,7 @@ use rustc_data_structures::snapshot_map::{self, SnapshotMapRef, SnapshotMapStora
 use rustc_data_structures::undo_log::Rollback;
 use rustc_middle::traits::EvaluationResult;
 use rustc_middle::ty;
+use tracing::{debug, info};
 
 use super::PredicateObligation;
 use crate::infer::snapshot::undo_log::InferCtxtUndoLogs;