Bump version to 0.7.4

This update fixes the `AttributeError: 'SOURCEOPS_OT_ExportAuto' object has no attribute '_lock'` error that happens sometimes.

__init__.py

@@ -3,7 +3,7 @@
     'author': 'bonjorno7, Almaas, Cabbage McGravel, CryptAlchemy, Gorange, Krystian, RED_EYE, SethTooQuick, Yonder',
     'description': 'A more convenient alternative to Blender Source Tools',
     'blender': (2, 83, 0),
-    'version': (0, 7, 3),
+    'version': (0, 7, 4),
     'location': '3D View > Sidebar',
     'category': 'Import-Export',
 }