chore: run update tests single threaded

Author: vmx

.github/workflows/ci.yml

@@ -86,8 +86,7 @@ jobs:
       - name: Run isolated update tests in release profile
         # Some `storage-proofs-update` tests need to run sequentially due to
         # their high memory usage.
-        #cargo test --release -p storage-proofs-update --features isolated-testing ${{ matrix.cargo-args }} -- --test-threads=1
-        run: cargo test --release -p storage-proofs-update --features isolated-testing ${{ matrix.cargo-args }} -- --nocapture
+        run: cargo test --release -p storage-proofs-update --features isolated-testing ${{ matrix.cargo-args }} -- --nocapture --test-threads=1
 
   #test_ignored_release:
   #  runs-on: ubuntu-latest