[3.11] gh-108822: Fix regrtest clear_caches() (#109432)

gh-108822: Fix regrtest clear_caches()

Python 3.11 doesn't have fractions._hash_algorithm cache.

Author: vstinner

Lib/test/libregrtest/utils.py

@@ -212,13 +212,6 @@ def clear_caches():
         for f in typing._cleanups:
             f()
 
-    try:
-        fractions = sys.modules['fractions']
-    except KeyError:
-        pass
-    else:
-        fractions._hash_algorithm.cache_clear()
-
 
 def get_build_info():
     # Get most important configure and build options as a list of strings.