MAINTAINERS: add the VFS git tree

The VFS git tree is missing from MAINTAINERS.  Add it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240820195109.38906-1-ebiggers@kernel.orgSigned-off-by: Christian Brauner <brauner@kernel.org>

MAINTAINERS

@@ -8597,6 +8597,7 @@ M:	Christian Brauner <brauner@kernel.org>
 R:	Jan Kara <jack@suse.cz>
 L:	linux-fsdevel@vger.kernel.org
 S:	Maintained
+T:	git https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
 F:	fs/*
 F:	include/linux/fs.h
 F:	include/linux/fs_types.h