Add backtrace line 0 to 3.4 ERB failure logs

Ruby 3.4 no longer provides the line number in the exception message
for the error raised by a failure to parse ERB in the newrelic.yml file.

To help our customers with debugging, add the line number to the output
by printing the first line of the backtrace for the exception to the
agent logs

Resolves #2902

lib/new_relic/agent/configuration/yaml_source.rb

@@ -99,7 +99,10 @@ def process_erb(file)
             file.gsub!(/^\s*#.*$/, '#')
             ERB.new(file).result(binding)
           rescue ScriptError, StandardError => e
-            log_failure('Failed ERB processing configuration file. This is typically caused by a Ruby error in <% %> templating blocks in your newrelic.yml file.', e)
+            message = 'Failed ERB processing configuration file. This is typically caused by a Ruby error in <% %> templating blocks in your newrelic.yml file.'
+            failure_array = [message, e]
+            failure_array << e.backtrace[0] if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('3.4.0')
+            log_failure(*failure_array)
             nil
           end
         end

test/multiverse/suites/config_file_loading/Envfile

@@ -4,15 +4,10 @@
 
 omit_collector!
 
-# TODO: RUBY 3.4
-# The CI has a prism-related error when it tries to run this suite
-# The problem may be a bug fixed in future preview releases
-# Disable ths suite for now, and try again when the next version
-# is out.
 PSYCH_VERSIONS = [
-  [nil, 2.4, 3.3],
-  ['4.0.0', 2.4, 3.3],
-  ['3.3.0', 2.4, 3.3]
+  [nil],
+  ['4.0.0'],
+  ['3.3.0']
 ]
 
 def stringio_version

test/multiverse/suites/config_file_loading/config_file_loading_test.rb

@@ -158,10 +158,6 @@ def test_warning_logged_when_config_file_yaml_parsing_error
     assert_log_contains(log, /ERROR.*Failed to read or parse configuration file at config\/newrelic\.yml/)
   end
 
-  # TODO: RUBY 3.4 SUPPORT
-  # Both error class and output have changes in Ruby 3.4
-  # See Issue: https://github.com/newrelic/newrelic-ruby-agent/issues/2902
-  unless Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('3.4.0')
     def test_warning_logged_when_config_file_erb_error
       path = File.join(@cwd, 'config', 'newrelic.yml')
       setup_config(path, {}, "\n\n\n<%= this is not ruby %>") # the error is on line 4
@@ -172,7 +168,6 @@ def test_warning_logged_when_config_file_erb_error
       assert_log_contains(log, /ERROR.*Failed ERB processing/)
       assert_log_contains(log, /\(erb\):4/)
     end
-  end
 
   def test_exclude_commented_out_erb_lines
     config_contents = <<~YAML