Issue #11727, issue #11753, issue #11755: disable regrtest timeout

Disable regrtest timeout until #11753 and #11755 are fixed
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 704ad77..bc67f78 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -240,7 +240,7 @@
          findleaks=False, use_resources=None, trace=False, coverdir='coverage',
          runleaks=False, huntrleaks=False, verbose2=False, print_slow=False,
          random_seed=None, use_mp=None, verbose3=False, forever=False,
-         header=False, timeout=30*60):
+         header=False, timeout=None):
     """Execute a test suite.
 
     This also parses command-line options and modifies its behavior