Add gir1.2-webkit2-4.0 as a dependency

[andrewharvey]

I found on Debian I needed to install gir1.2-webkit2-4.0 otherwise I got the error:

** (eog:332936): WARNING **: 19:12:55.348: Error importing plugin 'eog_panorama':
Traceback (most recent call last):
  File "/usr/lib/python3.11/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1204, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1176, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1147, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 940, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/home/user/.local/share/eog/plugins/eog_panorama/eog_panorama.py", line 28, in <module>
    gi.require_version('WebKit2', '4.0')
  File "/usr/lib/python3/dist-packages/gi/__init__.py", line 129, in require_version
    raise ValueError('Namespace %s not available for version %s' %
ValueError: Namespace WebKit2 not available for version 4.0

(eog:332936): libpeas-WARNING **: 19:12:55.348: Error loading plugin 'eog_panorama'