Revert "Refactor the logic of require 'erb/escape' (#61)"

This reverts commit 1c393aa.

Author: k0kubun

lib/erb/util.rb

@@ -8,11 +8,14 @@
 # TruffleRuby: lib/truffle/cgi/escape.rb requires 'cgi/util'.
 require 'cgi/escape'
 
-# Load or define ERB::Escape#html_escape.
-# We don't build the C extention 'cgi/escape' for JRuby, TruffleRuby, and WASM.
-if $LOAD_PATH.resolve_feature_path('erb/escape')
-  require 'erb/escape'
-else
+begin
+  # We don't build the C extension for JRuby, TruffleRuby, and WASM
+  if $LOAD_PATH.resolve_feature_path('erb/escape')
+    require 'erb/escape'
+  end
+rescue LoadError # resolve_feature_path raises LoadError on TruffleRuby 22.3.0
+end
+unless defined?(ERB::Escape)
   # ERB::Escape
   #
   # A subset of ERB::Util. Unlike ERB::Util#html_escape, we expect/hope