Revert "Add default exceptions affected by suppress (#25099)"

This reverts commit 28492204ee.

Reason: `suppress` without an argument doesn't actually tell what is
supressing. Also, it can be confused with ActiveRecord::Base#suppress.

activesupport/lib/active_support/core_ext/kernel/reporting.rb

@@ -37,7 +37,6 @@ module Kernel
   #
   #   puts 'This code gets executed and nothing related to ZeroDivisionError was seen'
   def suppress(*exception_classes)
-    exception_classes = StandardError if exception_classes.empty?
     yield
   rescue *exception_classes
   end

activesupport/test/core_ext/kernel_test.rb

@@ -42,15 +42,6 @@ class KernelSuppressTest < ActiveSupport::TestCase
     end
   end
 
-  def test_suppress_with_defaults
-    suppress { raise RuntimeError }
-    suppress { raise ArgumentError }
-
-    assert_raise(LoadError) do
-      suppress { raise LoadError }
-    end
-  end
-
   def test_suppression
     suppress(ArgumentError) { raise ArgumentError }
     suppress(LoadError) { raise LoadError }