Relay returning too many connection edges from QueryRenderer

Hi there. I'm trying to build a windowed pagination component and I've discovered a regression(?) when upgrading from compat to modern.

Because Relay doesn't support windowed pagination natively, I implemented it using `QueryRenderer`s manually keeping track of the `endCursor`. This worked with a compat `QueryRenderer`, but once I upgraded to modern this stopped working as expected.

In this first screenshot you can see what the `QueryRenderer` is returning in terms of props. This is the first "page" after requesting the first 2 edges in the connection.

In this next screenshot you can see that we are requesting the next "page" which is the next 2 edges in the connection after the `endCursor` of the prev "page".

**What happened in compat**

We would receive props which only contained only the two new edges. This is exactly what we requested and what we want.

**What's happening in modern**

We are _actually_ receiving 4 edges. The 2 from the prev page and the 2 from the next page of results. This makes is so that instead of windowed pagination we are instead making it a infinitely growing list.

This doesn't seem like the correct behavior. I would expect that we would only get props related to the variables I gave the `QueryRenderer` not additional edges that wasn't part of the request / response from the server.

Start with the QueryRenderer behavior described in the issue and reproduce the two-page windowed pagination flow using endCursor, comparing compat with modern. Inspect how the modern QueryRenderer handles connection edges across requests; done means the second request exposes only its two requested edges rather than retaining the previous page.

Written by the indexing model from the issue text.