Fedora 33: reduce concurrency

... to avoid OOM. E.g.:

as: out of memory allocating 4064 bytes after a total of 396447744 bytes
64 jobs for 2.12.2-1 in 52 minutes and 35 seconds (queued for 55 seconds)
latest
Status Job ID Name Coverage
  Build
passed build/centos/6 #79460
docker

00:15:52

passed build/centos/7 #79459
docker

00:25:05

passed build/centos/8 #79458
docker

00:18:36

passed build/fedora/29 #79465
docker

00:21:38

passed build/fedora/30 #79464
docker

00:24:39

passed build/fedora/31 #79463
docker

00:26:52

passed build/fedora/32 #79462
docker

00:29:31

passed build/fedora/33 #79461
docker

00:44:12

passed build/opensuse/15.0 #79473
docker

00:16:33

passed build/opensuse/15.1 #79472
docker

00:17:03

passed build/opensuse/15.2 #79471
docker

00:13:53

passed build/sles/12.4 #79470
docker

00:17:23

passed build/sles/12.5 #79469
docker

00:21:39

passed build/sles/15.0 #79468
docker

00:22:21

passed build/sles/15.1 #79467
docker

00:18:38

passed build/sles/15.2 #79466
docker

00:21:33

 
  Test
passed test/centos/6 #79476
docker

00:02:16

passed test/centos/7 #79475
docker

00:01:41

passed test/centos/8 #79474
docker

00:01:00

passed test/fedora/29 #79481
docker

00:02:16

passed test/fedora/30 #79480
docker

00:02:25

passed test/fedora/31 #79479
docker

00:02:38

passed test/fedora/32 #79478
docker

00:02:16

passed test/fedora/33 #79477
docker

00:02:14

passed test/opensuse/15.0 #79489
docker

00:02:29

passed test/opensuse/15.1 #79488
docker

00:02:18

passed test/opensuse/15.2 #79487
docker

00:02:44

passed test/sles/12.4 #79486
docker

00:03:20

passed test/sles/12.5 #79485
docker

00:03:02

passed test/sles/15.0 #79484
docker

00:05:56

passed test/sles/15.1 #79483
docker

00:06:18

passed test/sles/15.2 #79482
docker

00:03:17

 
  Upload
passed upload/SUSE/12.4 #79603
docker

00:00:18

passed upload/SUSE/12.5 #79604
docker

00:00:25

passed upload/SUSE/15.0 #79605
docker

00:00:24

passed upload/SUSE/15.1 #79606
docker

00:00:19

passed upload/SUSE/15.2 #79607
docker

00:00:25

passed upload/epel/6 #79608
docker

00:00:19

passed upload/epel/7 #79609
docker

00:00:23

passed upload/epel/8 #79610
docker

00:00:29

passed upload/fedora/29 #79611
docker

00:00:29

passed upload/fedora/30 #79612
docker

00:00:32

passed upload/fedora/31 #79613
docker

00:00:32

passed upload/fedora/32 #79614
docker

00:00:32

passed upload/fedora/33 #79615
docker

00:00:32

passed upload/openSUSE/15.0 #79616
docker

00:00:24

passed upload/openSUSE/15.1 #79617
docker

00:00:24

passed upload/openSUSE/15.2 #79618
docker

00:00:24

canceled upload/SUSE/12.4 #79502
docker

canceled upload/SUSE/12.5 #79501
docker

canceled upload/SUSE/15.0 #79500
docker

canceled upload/SUSE/15.1 #79499
docker

canceled upload/SUSE/15.2 #79498
docker

canceled upload/epel/6 #79492
docker

canceled upload/epel/7 #79491
docker

canceled upload/epel/8 #79490
docker

canceled upload/fedora/29 #79497
docker

canceled upload/fedora/30 #79496
docker

canceled upload/fedora/31 #79495
docker

canceled upload/fedora/32 #79494
docker

canceled upload/fedora/33 #79493
docker

canceled upload/openSUSE/15.0 #79505
docker

canceled upload/openSUSE/15.1 #79504
docker

canceled upload/openSUSE/15.2 #79503
docker