Hlt1Conf.dump_for_standalone_allen fails

I suspect something was not complete with !1318 (merged) as the Hlt1Conf.dump_for_standalone_allen test fails in master with

unexpected file size mismatch(es), Exception in validator

Traceback (most recent call last):
  File "/workspace/build/LHCb/InstallArea/x86_64_v2-centos7-gcc11-opt/python/GaudiConf/QMTest/LHCbTest.py", line 306, in ValidateOutput
    return super(LHCbTest, self).ValidateOutput(stdout, stderr, result)
  File "/workspace/build/Gaudi/InstallArea/x86_64_v2-centos7-gcc11-opt/python/GaudiTesting/QMTTest.py", line 137, in ValidateOutput
    exec(self.validator, globals(), exported_symbols)
  File "<string>", line 31, in <module>
  File "<string>", line 31, in <listcomp>
NameError: name 'pat' is not defined

It may seem that pat should be defined but there is an issue with how the validator code is being exec-ed. It should be enough to wrap the code in a function so that pat is a local variable within the function's scope.