Add Cachine & JUnit reporting to CI

.gitlab-ci.yaml

 image: rust:1.82-alpine
 stages:
   - test
+cache: &global_cache
+  key: ${CI_COMMIT_REF_SLUG}
+  paths:
+    - .cargo/bin
+    - .cargo/registry/index
+    - .cargo/registry/cache
+    - target/debug/deps
+    - target/debug/build
+  policy: pull-push
+
+variables:
+  CARGO_HOME: ${CI_PROJECT_DIR}/.cargo
 
 lint:
   stage: test
   script:
     - cargo fmt --all --check
     - cargo clippy --offline --frozen --locked -- -D warnings
+  cache:
+    <<: *global_cache
+    policy: pull
 
 test:
   stage: test
   script:
-    - cargo test
+    - cargo install junitify
+    - cargo test -- --format=json -Z unstable-options --report-time | junitify --out $CI_PROJECT_DIR/tests/
+  artifacts:
+    when: always
+    reports:
+      junit: $CI_PROJECT_DIR/tests/*.xml
 
 package:
   stage: test