aggregator: drop drain queries after sinkpad is drained.

It makes no sense to drain downstream when only a single sink pad
was drained, and it is impossible to "drain all sink pads" in a
thread safe way.

If the user wants downstream to be drained as well, they should
drain all sinkpads, then drain downstream.
8 jobs for aggregator-drop-drain-query in 31 minutes and 15 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Preparation
passed #178217
gst indent

00:00:35

passed #178216
manifest

00:00:24

 
  Build
passed #178218
build fedora x86_64

00:03:56

 
  Test
passed #178219
check fedora

00:03:40

 
  Full Builds
passed #178221
build cerbero android universal

00:23:01

passed #178222
build cerbero cross win32

00:10:32

passed #178223
build cerbero cross win64

00:06:21

passed #178220
build cerbero fedora x86_64

00:09:28