upgrade all Cargo.toml files to edition=2021

The MSRV is already 1.60, so this doesn't affect much. The only impact
to other code is that we no longer need to explicitly import TryInto.

1 files changed, 1 insertions, 1 deletions

diff --git a/Cargo.toml b/Cargo.toml
index d3e4371..40b1f81 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,7 +7,7 @@ repository = "https://github.com/BLAKE3-team/BLAKE3"
 license = "CC0-1.0 OR Apache-2.0"
 documentation = "https://docs.rs/blake3"
 readme = "README.md"
-edition = "2018"
+edition = "2021"
 
 [features]
 default = ["std"]