chore: remove author-specific gitignore stuff

Which was accidentally committed.

.gitignore

@@ -79,7 +79,3 @@ rebar-git-cache.tar
 apps/emqx_utils/src/emqx_variform_parser.erl
 apps/emqx_utils/src/emqx_variform_scan.erl
 default-profile.mk
-# local
-/_compat
-/scratch
-SCRATCH