.github: sync the list of paths for rbd label with CODEOWNERS

.github: sync the list of paths for rbd label with CODEOWNERS

With https://github.com/actions/labeler/issues/483 still pending, do it
manually.

A couple of entries matching both files and directories were expanded
since, unlike fnmatch(3), minimatch treats slashes specially:

- src/include/rbd* -> src/include/rbd* src/include/rbd/**
- src/rbd*         -> src/rbd* src/rbd*/**
- src/test/rbd*    -> src/test/rbd* src/test/rbd*/**

A bunch of entries under src/tools were combined into:

- src/tools/rbd*/**

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>