fix: resolve exclusion more deterministically in Check resolution

[jon-whit]

Description

Resolve non-deterministic resolution of Check queries with relations involving exclusion.

Given a definition a but not b and concurrent resolution of both branches a and b, then the following should occur:

• If a resolves to an {allowed: false} outcome we should short-circuit and return. No further resolution of b is necessary.
• If b resolves to an {allowed: true} outcome we should short-circuit and return. No further resolution of a is necessary.
• If a returns an error first, we must wait for b to resolve, because if b resolves to {allowed: true} the outcome should be {allowed: false}, because we can resolve this with a deterministic outcome.
• If b returns an error first, we must wait for a to resolve, because of a resolves to {allowed: false} the outcome should be {allowed: false}, because we can resolve this with a deterministic outcome.

References

Closes #1238

Review Checklist

• I have clicked on "allow edits by maintainers".
• I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• The correct base branch is being used, if not main
• I have added tests to validate that the change in functionality is working as expected

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (92324d8) 82.64% compared to head (0d0dba1) 82.64%.

Files	Patch %	Lines
internal/graph/check.go	76.93%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1239      +/-   ##
==========================================
+ Coverage   82.64%   82.64%   +0.01%     
==========================================
  Files          84       84              
  Lines        9736     9746      +10     
==========================================
+ Hits         8045     8054       +9     
- Misses       1334     1336       +2     
+ Partials      357      356       -1     

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