Bump MSTest.TestAdapter from 1.2.1 to 2.1.2

Bumps [MSTest.TestAdapter](https://github.com/microsoft/testfx) from 1.2.1 to 2.1.2.
- [Release notes](https://github.com/microsoft/testfx/releases)
- [Commits](microsoft/testfx@v1.2.1...v2.1.2)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

GraphODataTemplateWriter.Test/packages.config

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="MSTest.TestAdapter" version="1.2.1" targetFramework="net472" />
+  <package id="MSTest.TestAdapter" version="2.1.2" targetFramework="net472" />
   <package id="MSTest.TestFramework" version="1.2.1" targetFramework="net472" />
 </packages>