Image disabling statistics for July:
```
mysql:research@analytics-store.eqiad.wmnet [log]> select count(*), event_images from MobileOptionsTracking_8101982 where timestamp like '201507%' group by event_images;
+----------+--------------+
| count(*) | event_images |
+----------+--------------+
| 737033 | nochange |
| 113 | off |
| 131 | on |
+----------+--------------+
3 rows in set (5.81 sec)
```
This means that this functionality is barely ever used and maintaining it (cf T107368 and T109286) takes more effort than the good it brings. Therefore, it makes sense to remove it. Ping Zero just in case (it shouldn't affect ZeroBanner that removes images on its own, but oh well).
= Acceptance criteria
[x] When I visit Special:MobileOptions I do not see the "disable images" feature.
[x] Drop any code relating to the feature in MobileFrontend
[x] Drop any code relating to the feature in WikidataPageBanner
[x] Drop any code relating to the feature in Zero
^ There are no other extensions that rely on or set `wgDisableImages`: https://github.com/search?q=org%3Awikimedia+wgImagesDisabled&type=Code
= Sign off steps
[] Decline any subtasks implicated by this decision
= Post-deploy steps (Thursday, 22nd June)
[] Remove the `images` property from [the MobileOptionsTracking schema](https://meta.wikimedia.org/wiki/Schema:MobileOptionsTracking).
= Note:
~~If for some reason we decide to keep this feature, we will need to revisit the decision in T122267.~~ N/A