test-bot: run brew tests in no-compat mode

Closes Homebrew/homebrew#42009.

Signed-off-by: Xu Cheng <xucheng@me.com>

Library/Homebrew/cmd/test-bot.rb

@@ -560,6 +560,7 @@ module Homebrew
       @category = __method__
       return if ARGV.include? "--skip-homebrew"
       test "brew", "tests"
+      test "brew", "tests", "--no-compat"
       readall_args = []
       readall_args << "--syntax" if MacOS.version >= :mavericks
       test "brew", "readall", *readall_args

Library/Homebrew/cmd/tests.rb

@@ -3,6 +3,7 @@ module Homebrew
     (HOMEBREW_LIBRARY/"Homebrew/test").cd do
       ENV["TESTOPTS"] = "-v" if ARGV.verbose?
       ENV["HOMEBREW_TESTS_COVERAGE"] = "1" if ARGV.include? "--coverage"
+      ENV["HOMEBREW_NO_COMPAT"] = "1" if ARGV.include? "--no-compat"
       Homebrew.install_gem_setup_path! "bundler"
       quiet_system("bundle", "check") || \
         system("bundle", "install", "--path", "vendor/bundle")