chore: Add some tests

.gitea/workflows/ci.yml

@@ -189,8 +189,9 @@ jobs:
             ${{ runner.os }}-bun-
       - run: apt update && apt install just -y
       - run: bun add -g concurrently
-      - run: curl https://sh.rustup.rs -sSf | sh -s -- -y
-      - run: cargo install --locked watchexec-cli
+      - uses: taiki-e/cache-cargo-install-action@v2
+        with:
+          tool: watchexec-cli
       - name: Install dependencies
         run: |
           cd frontend