relation immediately
Texture and ParticleSettings have a DEG relation, but
`DEG_relations_tag_update` was not called when the texture changed.
This lead to no updates when e.g. texture size changes, relation only
went into full effect after save/reload or adding/removing keyframes.
Two places were additional relation tagging is needed:
- ParticleSettings `active_texture` changes
- ParticleSettingsTextureSlot (basically any TextureSlots') texture
changes
Maniphest Tasks: T82242
Differential Revision: https://developer.blender.org/D9393