ci: add missing install deps step

Author: heeeyflo

.github/workflows/tests.yml

@@ -9,6 +9,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: oven-sh/setup-bun@v2
+      - run: bun install --frozen-lockfile
       - run: bun lint
       - run: bun test
       - run: bun run typecheck