How to reproduce:
1. Open the attached "IN-148299_test_project_auditor.zip" project
2. Open the Project Auditor (Window -> Analysis -> Project Auditor)
3. Press "Start Analysis"
4. Wait for the analysis to complete
5. On the left of the Project Auditor window, press "Code", then "Compiler Messages"
6. Observe the issue list
Actual result: A "CS8773 Feature 'global using directive' is not available in C# 9.0. Please use language version 10.0 or greater." error is displayed in the list
Expected result: No errors are present in the list
Reproducible with: 6000.0.0f1, 6000.0.79f1, 6000.3.20f1, 6000.5.4f1, 6000.6.0b4, 6000.7.0a2
Reproducible on: Windows 11
Not reproducible on: No other environments tested
Note: The file "csc.rsp" specifies that language version used is C# 10: "-LangVersion:10"