builtins/formatting: Remove -f in sqlfluff (#95)

This became the default in 3.x.

https://github.com/sqlfluff/sqlfluff/blob/main/docs/source/releasenotes.rst#upgrading-to-3x

Author: chaozwn

lua/null-ls/builtins/formatting/sqlfluff.lua

@@ -25,7 +25,6 @@ local sources = {
         args = {
             "fix",
             "--disable-progress-bar",
-            "-f",
             "-n",
             "-",
         },