Not only CSV extensions are linked to Entity lists.

#### Problem description
Not only CSV extensions are linked to Entity lists.

#### Steps to reproduce the problem
1. Publish a form creating a dataset (e.g. itemsets.csv).
[itemsets_registration.xml.zip](https://github.com/getodk/central/files/12495497/itemsets_registration.xml.zip)
2. Upload a form (not updating entities) that attaches a geojson file with the same name (e.g. itemsets.geojson).
[SelectOneFromMapTestFormitemset.xlsx.txt](https://github.com/getodk/central/files/12495511/SelectOneFromMapTestFormitemset.xlsx.txt)
3. In the Draft section go to Form Attachments tab and check if there is a button suggesting linking itemsets.geojson file to the Entity list.
#### Screenshot

#### Expected behavior
Only CSV extensions should be link to Entity lists.
#### Central version shown in version.txt
https://test.getodk.cloud/
versions:
906addf66af230735e501ad73a1269012fdd7a5a (v2023.3.1)
+330132cf1ecb824b1fb88894287cb8edb5acefa5 client (v2023.3.0-2-g330132cf)
ba6ee474f431b48e885fb035c9266792f06d0ad7 server (v2023.3.1)
https://staging.getodk.cloud/
versions:
f78da7a8b7a132ad2baa794a656da6ba8e40754a (v2023.3.1-6-gf78da7a)
+f6aefcc71621a394943f91613234ba295e34cd86 client (v2023.3.0-17-gf6aefcc7)
+628ac0d14e4c772591661dbac81b1fb49a1dbce8 server (v2023.3.1-34-g628ac0d1)

#### Browser version

Chrome 114.0.5735.198, Firefox 116.0.2