Merge branch 'clippy' into 'main'

Fix clippy lints and add clippy to CI

See merge request iwj/hippotat!74

diff --cc .gitlab-ci.yml
index f6ba478f6a4fd1665f75034dcac94530a3373827,db32a50dd08c4f2c53099260575f61df36c5769f..f69d61f841a2399d16194dd47a3dc8bbf40208d8
--- 1/.gitlab-ci.yml
--- 2/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@@ -24,8 -24,17 +24,17 @@@ cargo-test
    stage: test
    image: "rust:latest"
    script:
 -    - cargo test --locked --workspace --verbose --all-features
 +    - cargo test --locked --workspace --all-features
  
+ cargo-clippy:
+   stage: test
+   # This can fail when new lints turn up.  So we pin the compiler.
+   # We should update this (when we switch from trixie to forky, at least).
+   image: "rust:1.95.0"
+   script:
+     - rustup component add clippy
+     - cargo clippy --locked --workspace --all-features
+ 
  cargo-update-test-nightly:
    stage: test
    image: "rustlang/rust:nightly"