Add Cargo.lock to git

See https://blog.rust-lang.org/2023/08/29/committing-lockfiles.html

Author: konstin

.gitignore

@@ -2,10 +2,6 @@
 # will have compiled files and executables
 /target/
 
-# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
-# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-/Cargo.lock
-
 # These are backup files generated by rustfmt
 **/*.rs.bk