Deprecate unused constant in PharInvocationResolver

[ohader]

Constant ASSERT_INTERNAL_INVOCATION is not used anymore since eb6607f#diff-0dd07cb25bec3476d9fc1d8a3db389b3L59

Asserting internal alias invocation just did not work out in a simple example like this

require('/path/bundle.phar');
// which internally does e.g. include('phar://bndl/vendor/autoload.php')
// given that Phar stub loads `autoload.php` using an internal alias
$object = new BundledClass();