[nvim] Remove golang-ci metalinter, rely on vim-go

vim-go already provides the linting necessary for golang. Using
golang-ci additionally only complicates matters and provides no benefit.
Additionally, it did not seem to be able to track files other than the
one in the current buffer, or those open in hidden buffers and would
show (false) errors of classes or functions not found even when they
existed.

.config/nvim/init.vim

@@ -275,7 +275,7 @@ let g:ale_fixers = {
       \}
 
 let g:ale_linters = {
-      \ 'go': ['golangci-lint','gopls'],
+      \ 'go': ['gopls'],
       \ 'sh': ['language_server','shellcheck','shfmt'],
       \}