[V3] Fix build indeterminism by sorting entries

[mattcompiles]

Motivation

When building with multiple entries, builds could produce indeterministic outputs as the entries were attached to the graph in random order (due to concurrency). While entry order is not really an issue, it could cause Assets shared between entries to be visited earlier/later when running a DFS. This caused bundles to be changed between builds in some cases, for example manual shared bundle Asset order.

To resolve this, entries are now attached to the graph after the AssetGraph is built and in a sorted order (alphabetical by entry name).

Changes

• Attach entries to the AssetGraph after it's complete and in a sorted order
• Ensure we don't add duplicate edges to the graph when handling pending Assets
• Add tracing to serialize_asset_graph

Checklist

• Existing or new tests cover this change

[yamadapc]

The problem isn't on this graph, is on the other parts of the codebase which are depending on the order these edges and nodes exist in.

There is one known place which does this added in https://github.com/parcel-bundler/parcel/pull/9706/files

Here, instead of assetGraph.dfsFast which will depend on the order of nodes on the graph, we should be sorting them by some preset value (like ID or path). This is tracked by AFB-406 since that change was made.

I'd rather we try to fix that first. You would need to sort in that part instead of this.

[mattcompiles]

As discussed, I attempted to fix the individual places we rely on edge order but it became a risky and complicated fix that will take time to get right.

I've added a comment to explain the situation and we can look to remove the ordering code once the bundler has been replaced.