[V3] Optimize the backup command (#1666)

* [V3 Core] Enhance [p]backup to exclude some files

* Backup the repo list too

* Lol Sinbad's pre-commit hook

* Add option of sending the backup to the owner via DM

* Drop an unnecessary config object in RepoManager

* Move the backup functionality in redbot-setup to the new stuff

* More work on implementation, including backing up the instance data

redbot/cogs/downloader/downloader.py

@@ -50,7 +50,7 @@ class Downloader:
         if str(self.LIB_PATH) not in syspath:
             syspath.insert(1, str(self.LIB_PATH))
 
-        self._repo_manager = RepoManager(self.conf)
+        self._repo_manager = RepoManager()
 
     async def cog_install_path(self):
         """Get the current cog install path.

redbot/cogs/downloader/repo_manager.py

@@ -496,8 +496,7 @@ class Repo(RepoJSONMixin):
 
 class RepoManager:
 
-    def __init__(self, downloader_config: Config):
-        self.downloader_config = downloader_config
+    def __init__(self):
 
         self._repos = {}