CodeQL python setup fails when Python2 is not available

[cdivitotawela]

There is a problem with https://github.com/github/codeql-action/blob/main/python-setup/install_tools.sh#L31 where the python setup fails when the runner does not have python2 installed. Expectation is that when python2 is not installed code execution is not go into the if condition.

Installing collected packages: virtualenv-clone, pipenv
  Successfully installed pipenv-[202](https://github.com/ConsenSys/ethereum-prometheus-exporter/runs/5687749074?check_suite_focus=true#step:7:202)2.3.24 virtualenv-clone-0.5.7
  + + 
  command -v python2
  + + python2
  /runner/_work/_actions/github/codeql-action/v1/python-setup/install_tools.sh: 34: python2: not found
  curl --location --fail https://bootstrap.pypa.io/pip/2.7/get-pip.py
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  
    0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
    0 1863k    0  4113    0     0   143k      0  0:00:12 --:--:--  0:00:12  143k
  curl: (23) Failed writing body (1354 != 1371)