Update bug report templates to Rails 8.1 (8-1-stable branch)

Author: andynu

guides/bug_report_templates/active_record_gem.rb

@@ -7,7 +7,7 @@
 
   git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-  gem "activerecord", github: "rails/rails", branch: "8-0-stable"
+  gem "activerecord", github: "rails/rails", branch: "8-1-stable"
   gem "activerecord-oracle_enhanced-adapter",  github: "rsim/oracle-enhanced", branch: "release80"
   gem "minitest"
 

guides/bug_report_templates/active_record_gem_spec.rb

@@ -7,7 +7,7 @@
 
   git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-  gem "activerecord", github: "rails/rails", branch: "8-0-stable"
+  gem "activerecord", github: "rails/rails", branch: "8-1-stable"
   gem "activerecord-oracle_enhanced-adapter",  github: "rsim/oracle-enhanced", branch: "release80"
   gem "rspec", require: "rspec/autorun"