fix: bump MSRV in cargo

Author: andylokandy

Cargo.toml

@@ -10,7 +10,7 @@ readme = "README.md"
 edition = "2021"
 license = "Apache-2.0"
 repository = "https://github.com/fast/fastrace-tower"
-rust-version = "1.75"
+rust-version = "1.80"
 
 [dependencies]
 fastrace = "0.7"