imporve caching

.gitlab-ci.yml

@@ -9,7 +9,7 @@ before_script:
 rust-latest: &build_and_test
   stage: build
   cache:
-    key: shared-cache
+    key: cache-latest
     paths:
       - target/
   script:
@@ -19,6 +19,8 @@ rust-latest: &build_and_test
 rust-nightly: &rust_nightly
   <<: *build_and_test
   image: rustlang/rust:nightly
+  cache:
+    key: cache-nightly
   allow_failure: true
 
 clippy: