stats: remove tracking of expiring records

The predict module doesn't use this way since 965bab92 (v1.3.2),
and there seems to be no other likely use case.
16 jobs for predict_bugfix in 10 minutes and 6 seconds (queued for 7 seconds)
Status Job ID Name Coverage
  Build
passed #110022
docker linux amd64
build:clang:linux:amd64

00:00:29

passed #110021
docker linux amd64
build:linux:amd64

00:00:28

 
  Test
passed #110037
docker linux amd64
deckard:linux:amd64

00:06:30

passed #110028
docker
doc

00:00:20

passed #110027
docker linux amd64
installcheck:linux:amd64

00:01:10

passed #110030
docker linux amd64
installcheck:valgrind:linux:amd64

00:01:08

passed #110024
docker
lint:c

00:02:12

failed #110025
docker allowed to fail
lint:clang-scan-build

00:01:11

passed #110023
docker
lint:lua

00:00:27

passed #110033
docker linux amd64
respdiff:iter:tcp:linux:amd64

00:02:47

passed #110034
docker linux amd64
respdiff:iter:tls:linux:amd64

00:02:24

passed #110032
docker linux amd64
respdiff:iter:udp:linux:amd64

00:02:23

passed #110026
docker linux amd64
test:linux:amd64

00:00:59

passed #110031
docker linux amd64
test:linux:amd64:valgrind

00:00:25

failed #110029
docker linux amd64
deckard:linux:amd64

00:01:08

 
  Coverage
passed #110035
docker linux amd64
coverage

00:00:14

71.6%
 
Name Stage Failure
failed
lint:clang-scan-build Test
                                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 warnings generated.
CCLD daemon/kresd
scan-build: 22 bugs found.
scan-build: Run 'scan-view /builds/knot/knot-resolver/scan-results/2018-02-15-154222-13-1' to examine bug reports.
Uploading artifacts...
scan-results: found 27 matching files
Uploading artifacts to coordinator... ok
id=110025 responseStatus=201 Created token=AKpimTXJ
ERROR: Job failed: exit code 1