What modifications were needed to make vcenter_saml_login.py run directly on vCenter?

The script had to remove the dependency on the third-party `bitstring` package by inlining its functionality, and replace f-string formatting with the `.format()` method because vCenter 6.7 uses Python 3.5.6, which doesn't support f-strings. This allows the script to be uploaded and executed directly on a vCenter server without additional dependencies.