Add neovim 0.6 to run-tests (#3998)

* Update test scripts
* Remove neovim 0.3 and 0.4
* Add neovim 0.6.1

Co-authored-by: Horacio Sanson <horacio@allm.inc>
Co-authored-by: w0rp <devw0rp@gmail.com>

test/test_list_titles.vader

@@ -38,7 +38,7 @@ Execute(The loclist titles should be set appropriately):
   \ 'nr': 0,
   \ 'type': 'E',
   \ 'pattern': '',
-  \}], ale#test#GetLoclistWithoutModule()
+  \}], ale#test#GetLoclistWithoutNewerKeys()
 
   if !has('nvim')
     AssertEqual
@@ -68,7 +68,7 @@ Execute(The quickfix titles should be set appropriately):
   \ 'nr': 0,
   \ 'type': 'E',
   \ 'pattern': '',
-  \}], ale#test#GetQflistWithoutModule()
+  \}], ale#test#GetQflistWithoutNewerKeys()
 
   if !has('nvim')
     AssertEqual