ci: pin tracing-core in msrv job (#203)

Author: seanmonstar

.github/workflows/CI.yml

@@ -72,6 +72,7 @@ jobs:
           cargo update --package tokio-util --precise 0.7.11
           cargo update --package hashbrown --precise 0.15.0
           cargo update --package once_cell --precise 1.20.3
+          cargo update --package tracing-core --precise 0.1.33
       - name: Install Rust (${{ matrix.rust }})
         uses: dtolnay/rust-toolchain@master
         with: