Fix regrtest --coverage on Windows

Issue #25260: Fix ``python -m test --coverage`` on Windows. Remove the list of
ignored directories.
diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
index e1a99fb..c1ce3b1 100644
--- a/Lib/test/libregrtest/main.py
+++ b/Lib/test/libregrtest/main.py
@@ -272,10 +272,7 @@
     def run_tests_sequential(self):
         if self.ns.trace:
             import trace
-            self.tracer = trace.Trace(ignoredirs=[sys.base_prefix,
-                                                  sys.base_exec_prefix,
-                                                  tempfile.gettempdir()],
-                                      trace=False, count=True)
+            self.tracer = trace.Trace(trace=False, count=True)
 
         save_modules = sys.modules.keys()