Add checks to see if Dir.exists? and File.exists? are gone

They have been removed in Ruby 3.2 (Feature #17391)

core/dir/exist_spec.rb

@@ -13,3 +13,11 @@
 
   it_behaves_like :dir_exist, :exist?
 end
+
+ruby_version_is "3.2" do
+  describe "Dir.exists?" do
+    it "has been removed" do
+      Dir.should_not.respond_to?(:exists?)
+    end
+  end
+end

core/file/exist_spec.rb

@@ -4,3 +4,11 @@
 describe "File.exist?" do
   it_behaves_like :file_exist, :exist?, File
 end
+
+ruby_version_is "3.2" do
+  describe "File.exists?" do
+    it "has been removed" do
+      File.should_not.respond_to?(:exists?)
+    end
+  end
+end