Fix compatibility with Ubuntu 24.04

[tobias-richter]

I just stumbled about the following errors

2025-06-06 17:27:33: python.d ERROR: apt_updates[apt_updates] : Traceback (most recent call last):
  File "/usr/libexec/netdata/python.d/python_modules/bases/FrameworkServices/ExecutableService.py", line 80, in check
    data = self._get_data()
           ^^^^^^^^^^^^^^^^
  File "/usr/libexec/netdata/python.d/apt_updates.chart.py", line 50, in _get_data
    nr_updates = update_line[0].split(', ')[0]
                 ~~~~~~~~~~~^^^
TypeError: 'filter' object is not subscriptable

and

/usr/libexec/netdata/python.d/apt_updates.chart.py:54: SyntaxWarning: invalid escape sequence '\d'
  return {'apt_updates': re.search('\d+', nr_updates).group()}

so I thought I quickly fix these issues :)