Replace env variable PARALLEL_TESTS_EXECUTABLE with RSPEC_EXECUTABLE

Author: ilyazub

lib/turbo_tests/runner.rb

@@ -140,8 +140,8 @@ def start_subprocess(env, extra_args, tests, process_id, record_runtime:)
         env["RUBYOPT"] = ["-I#{File.expand_path("..", __dir__)}", ENV["RUBYOPT"]].compact.join(" ")
         env["RSPEC_SILENCE_FILTER_ANNOUNCEMENTS"] = "1"
 
-        if ENV["PARALLEL_TESTS_EXECUTABLE"]
-          command_name = ENV["PARALLEL_TESTS_EXECUTABLE"].split
+        if ENV["RSPEC_EXECUTABLE"]
+          command_name = ENV["RSPEC_EXECUTABLE"].split
         elsif ENV["BUNDLE_BIN_PATH"]
           command_name = [ENV["BUNDLE_BIN_PATH"], "exec", "rspec"]
         else