ci: drop pnpm cache from setup-node

The Gitea Actions cache server is unreachable from the runner, so
cache: pnpm hangs ~4m42s on ETIMEDOUT before falling through. Removing
the option drops the step to ~5s; pnpm install on a clean runner is
already fast with the frozen lockfile.

.gitea/workflows/ci.yaml

@@ -29,7 +29,6 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           node-version: ${{ env.NODE_VERSION }}
-          cache: pnpm
 
       - name: Install dependencies
         run: pnpm install --frozen-lockfile
@@ -75,7 +74,6 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           node-version: ${{ env.NODE_VERSION }}
-          cache: pnpm
 
       - run: pnpm install --frozen-lockfile
       - run: pnpm -C packages/db exec prisma generate