Bump EnvironmentAbstractions.TestHelpers from 2.1.0 to 3.0.2 (#554)

Bumps [EnvironmentAbstractions.TestHelpers](https://github.com/jeffkl/EnvironmentAbstractions) from 2.1.0 to 3.0.2.
- [Release notes](https://github.com/jeffkl/EnvironmentAbstractions/releases)
- [Commits](jeffkl/EnvironmentAbstractions@v2.1.0...v3.0.2)

---
updated-dependencies:
- dependency-name: EnvironmentAbstractions.TestHelpers
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Directory.Packages.props

@@ -17,7 +17,7 @@
   <ItemGroup>
     <PackageVersion Include="EnvironmentAbstractions" Version="3.0.2" />
     <PackageVersion Include="EnvironmentAbstractions.BannedApiAnalyzer" Version="3.0.2" />
-    <PackageVersion Include="EnvironmentAbstractions.TestHelpers" Version="2.1.0" />
+    <PackageVersion Include="EnvironmentAbstractions.TestHelpers" Version="3.0.2" />
     <PackageVersion Include="McMaster.Extensions.CommandLineUtils" Version="4.1.0" />
     <PackageVersion Include="Microsoft.Build" Version="$(MicrosoftBuildPackageVersion)" />
     <PackageVersion Include="Microsoft.Build.Runtime" Version="$(MicrosoftBuildPackageVersion)" />