Bump DocumentFormat.OpenXml from 2.20.0 to 3.5.1

---
updated-dependencies:
- dependency-name: DocumentFormat.OpenXml
  dependency-version: 3.5.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Directory.Packages.props

@@ -8,7 +8,7 @@
     <PackageVersion Include="AwesomeAssertions.Analyzers" Version="9.0.8" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.15.8" />
     <PackageVersion Include="coverlet.collector" Version="8.0.1" />
-    <PackageVersion Include="DocumentFormat.OpenXml" Version="[2.20.0,3.0.0)" />
+    <PackageVersion Include="DocumentFormat.OpenXml" Version="3.5.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.4.0" />
     <PackageVersion Include="Nerdbank.GitVersioning" Version="3.9.50" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />