add _logger.py to core

Author: mabdinur

tests/suitespec.yml

@@ -55,6 +55,7 @@ components:
     - ddtrace/internal/gitmetadata.py
     - ddtrace/internal/glob_matching.py
     - ddtrace/internal/logger.py
+    - ddtrace/_logger.py
     - ddtrace/internal/hostname.py
     - ddtrace/internal/http.py
     - ddtrace/internal/bytecode_injection/*