build(deps): bump xunit from 2.6.2 to 2.6.4 in /integrationtests (#3707)

Bumps [xunit](https://github.com/xunit/xunit) from 2.6.2 to 2.6.4.
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/xunit/xunit/commit/0f87ff772a29aa3d4ef7cb5b34a8aeeaab2c2a28"><code>0f87ff7</code></a>
v2.6.4</li>
<li><a
href="https://github.com/xunit/xunit/commit/e466a7c13337a93c07da6b3480f6637c005ccdc9"><code>e466a7c</code></a>
Unit tests for <a
href="https://redirect.github.com/xunit/xunit/issues/2850">#2850</a>
(v2)</li>
<li><a
href="https://github.com/xunit/xunit/commit/0cc026be3bc3a9f97dda99194b72e13f597e791b"><code>0cc026b</code></a>
Add KeyValuePair tests with collections and IEquatable objects in the
key slot</li>
<li><a
href="https://github.com/xunit/xunit/commit/c729d7fd799c7db658b2a0f7bb6c27a9ef252934"><code>c729d7f</code></a>
Add collection dictionary tests for IEquatable&lt;&gt; objects in the
value slot</li>
<li><a
href="https://github.com/xunit/xunit/commit/0eb76d2b780819865a3291d24d4eced6ed744002"><code>0eb76d2</code></a>
Attempt to fix race condition reported in <a
href="https://github.com/visualstudio.xunit/issues/issues/396">visualstudio.xunit/issues#396</a></li>
<li><a
href="https://github.com/xunit/xunit/commit/348c56ddd3e877e821e9a9f59918a1fbbab3ad45"><code>348c56d</code></a>
Bump up to v2.6.4-pre</li>
<li><a
href="https://github.com/xunit/xunit/commit/4c2c19380d12a1159e66ec543587b26574099beb"><code>4c2c193</code></a>
v2.6.3</li>
<li><a
href="https://github.com/xunit/xunit/commit/c4e29fdee2ba5c28f77d3a02f9efd56832427b0e"><code>c4e29fd</code></a>
<a
href="https://redirect.github.com/xunit/xunit/issues/2811">xunit/xunit#2811</a>:
Add tests for SortedSet and ImmutableSortedSet overloads fo...</li>
<li><a
href="https://github.com/xunit/xunit/commit/51851a64edb68040e8387f61c148b551a28b95e1"><code>51851a6</code></a>
Unit tests to ensure equality assertions with sets + comparer func throw
an e...</li>
<li><a
href="https://github.com/xunit/xunit/commit/ca683935df915c827d31ab07a4a17685235d9689"><code>ca68393</code></a>
Unit tests for <a
href="https://redirect.github.com/xunit/xunit/issues/2828">#2828</a>
(v2)</li>
<li>Additional commits viewable in <a
href="https://github.com/xunit/xunit/compare/2.6.2...2.6.4">compare
view</a></li>
</ul>
</details>
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integrationtests/IntegrationTests.Shared.Tests/IntegrationTests.Shared.Tests.csproj

@@ -9,7 +9,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="xunit" Version="2.6.2" />
+    <PackageReference Include="xunit" Version="2.6.4" />
     <PackageReference Include="xunit.runner.console" Version="2.6.4">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>