chore: Apply whitespace fixes from hooks

- Remove trailing whitespace
- Correct single newline at end of files (skip for json)
- Update to formatting in a few places due to black

help/en/developer/hscommon/index.rst

@@ -4,7 +4,7 @@ hscommon
 .. toctree::
     :maxdepth: 2
     :glob:
-    
+
     build
     conflict
     desktop
@@ -13,4 +13,3 @@ hscommon
     util
     jobprogress/*
     gui/*
-