Make descriptions match code for beginless range size specs

Author: rwstauner

spec/ruby/core/range/size_spec.rb

@@ -44,12 +44,12 @@
   end
 
   ruby_version_is "3.2" do
-    it 'returns Float::INFINITY for all beginless ranges if the start is numeric' do
+    it 'returns Float::INFINITY for all beginless ranges if the end is numeric' do
       (..1).size.should == Float::INFINITY
       (...0.5).size.should == Float::INFINITY
     end
 
-    it 'returns nil for all beginless ranges if the start is numeric' do
+    it 'returns nil for all beginless ranges if the end is not numeric' do
       (...'o').size.should == nil
     end