hash table implementation seems to be broken when using string key
While working on !78 (closed) a bug in the hash table implementation raised up !78 (comment 99978). Simply changing the key type from int to string for pollables (https://gitlab.freedesktop.org/rhabacker/dbus/commits/hash-table-string-key-issue) breaks watch management in mainloop.
see https://gitlab.freedesktop.org/rhabacker/dbus/pipelines/14269 for the failing jobs