Skip tests that would incorrectly fail valgrind

Author: peterzhu2118

test/rbs/test/runtime_test_test.rb

@@ -20,6 +20,10 @@ def test_runtime_test_with_sample_size
   end
 
   def test_runtime_test_error_with_invalid_sample_size
+    # Skip this test if running under Valgrind because `RUBY_FREE_AT_EXIT` has a bug.
+    # See: https://bugs.ruby-lang.org/issues/21173
+    omit if ENV["RUBY_MEMCHECK_RUNNING"]
+
     string_err_msg = refute_test_success(other_env: {"RBS_TEST_SAMPLE_SIZE" => 'yes'})
     assert_match(/E, .+ ERROR -- rbs: Sample size should be a positive integer: `.+`\n/, string_err_msg)
 
@@ -93,6 +97,9 @@ def refute_test_success(other_env: {}, rbs_content: nil, ruby_content: nil)
   end
 
   def test_test_target
+    # Skip this test if running under Valgrind because `RUBY_FREE_AT_EXIT` has a bug.
+    # See: https://bugs.ruby-lang.org/issues/21173
+    omit if ENV["RUBY_MEMCHECK_RUNNING"]
     output = refute_test_success(other_env: { "RBS_TEST_TARGET" => nil })
     assert_match "test/setup handles the following environment variables:", output
   end