main/xvfb-run: Add coreutils as dependency to avoid missing fmt

xvfb-run needs fmt, this binary is part of the coreutils package. So coreutils
must be added as a dependency to ensure proper operation even in the
error case.

Signed-off-by: Gustavo L F Walbon <gwalbon@linux.ibm.com>
Signed-off-by: Mike Sullivan <mksully22@gmail.com>
7 jobs for !3036 with fmtmiss in 6 minutes and 17 seconds (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Lint
passed #36005
docker-alpine x86_64
lint

00:00:32

 
  Build
passed #36010
docker-alpine ci-build aarch64
build-aarch64

00:01:42

passed #36011
docker-alpine ci-build armv7
build-armv7

00:01:22

passed #36009
docker-alpine ci-build ppc64le
build-ppc64le

00:01:27

passed #36008
docker-alpine ci-build s390x
build-s390x

00:00:25

passed #36007
docker-alpine ci-build x86
build-x86

00:00:24

passed #36006
docker-alpine ci-build x86_64
build-x86_64

00:00:22