lib: Fix examples not working

Remove the sanity check added in commit b1afa9da, having a poll setup
isn't necessary to use timeouts, as long as only sync functions are
used.

Closes: #139
2 jobs for wip/hadess/timeout-no-poll in 7 minutes and 8 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #70618
build

00:02:43

 
  Test
passed #70619
flatpak master

00:04:24