Obsidian plugin on an Enable/Disable loop.

**Describe the bug**
Installing the and enabling the plugin on Obsidian causes itself to enter a loop where it keeps enabling and disabling itself. This causes the spellchecks to flicker and make it unusable.

**To Reproduce**
1. Install the Harper plugin at the community plugins section.
2. Enable the plugin.

**Screenshots**

**Platform**
Obsidian 1.12.7 on Linux (CachyOS)
Harper 2.6.0

**Additional context**
Tried `2.6.0`, `2.5.0`, and `2.4.0`, all of them had the same behavior. Didn't have time to test other versions.
I did notice that the settings page for harper also does some weird refreshing every time the disable/enable cycle happen.
I did some very surface level investigation putting some breakpoints around on the dev tools inside obsidian and it seems that `onExternalSettingsChange` is called periodically, causing it to call `reloadSettingsFromDisk`, which causes the disable/enable.
It happens regardless without any other plugins installed as well.

Reproduce the loop with Harper 2.6.0 in Obsidian on Linux, then trace the reported onExternalSettingsChange and reloadSettingsFromDisk path. Check why the settings refresh triggers repeated enable/disable events; done means the plugin remains enabled, spellchecking stays stable, and the settings page no longer refreshes continuously.

Written by the indexing model from the issue text.