test: stop awaiting act()

[pjonsson]

What this PR does

This fixes the warning:

Do not await the result of calling act(...) with sync logic, it is not a Promise.

Test me

Tests only update.

Checklist

• There are unit tests to verify my changes are correct or unit tests aren't applicable (if so, write quick reason why unit tests don't exist)
• I've updated relevant documentation in doc/.
• I've updated CHANGES.md with what I changed.
• I've provided instructions in the PR description on how to test this PR.

[na9da]

Luckily in this case the ItemSearchTool component accepts an afterLoad callback, so we can use it to wait on.
Something like this should work:

    let renderPromise: Promise<void> | undefined;
    act(() => {
      renderPromise = new Promise((resolve) => render({
        item,
        itemSearchProvider,
        viewState,
        afterLoad: resolve
      }));
    });
    await renderPromise;

[pjonsson]

Added a commit with the suggestion and the tests now pass, thanks!

[na9da]

@pjonsson - thanks as always for your PRs, I have added a suggestion to fix the ItemSearchProviderSpec.

[pjonsson]

As a beginner it's hard to know where to look because of all the warnings (and easy to miss something essential). I'm guessing this PR falls somewhere between trivial and requires testing/effort, but it would be nice if the trivial stuff like #7134, #7136, and TerriaJS/terriajs-server#158 could get merged.

[na9da]

Looks good, merging.