Godot 4: fix infinite import/compilation loop

[olanti-p]

Fix infinite loop that happens when the addon detects resource import, fires compilation, then detects a new import of produced .jsons and fires compilation again.

The fix is to use ink_resources_reimported signal that only fires when .ink resources are reimported, opposed to editor filesystem signal that fires on any resource reimport.

Opportunistically fix the typo.

Tested on personal project under Godot 4.3. Didn't run any tests.