[datahopper] Call TaskCfgCache.Cleanup()
[datahopper] Call TaskCfgCache.Cleanup()

Related to https://skia-review.googlesource.com/c/buildbot/+/98701

Bug: skia:7520
Change-Id: Ic15beb09d20c9687ccb35562a18bf5ee0bf6b5aa
Reviewed-on: https://skia-review.googlesource.com/105611
Commit-Queue: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@google.com>
Reviewed-by: Ben Wagner <3ef7217be91069877d94f7907ce5479000772cd3@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot