gitlab-ci: Allow Windows builds to fail again

Due to T7702 and the process issues described in #17777.
22 jobs for master in 28 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Lint
canceled #253993
lint
lint-linters

00:00:28

canceled #253996
lint
lint-submods-branch

canceled #253994
lint
lint-testsuite

00:00:27

canceled #253995
lint
typecheck-testsuite

 
  Quick Build
canceled #253997
x86_64-linux
hadrian-ghc-in-ghci

 
  Build
canceled #253998
x86_64-linux
validate-x86_64-linux-deb9-hadrian

 
  Full Build
canceled #254001
aarch64-linux allowed to fail
validate-aarch64-linux-deb9

canceled #254002
armv7-linux
validate-armv7-linux-deb9

canceled #254003
x86_64-linux
validate-i386-linux-deb9

canceled #254000
x86_64-darwin
validate-x86_64-darwin

canceled #254004
x86_64-linux
validate-x86_64-linux-deb9-debug

canceled #254006
x86_64-linux
validate-x86_64-linux-deb9-dwarf

canceled #254005
x86_64-linux
validate-x86_64-linux-deb9-integer-simple

canceled #253999
x86_64-linux
validate-x86_64-linux-deb9-unreg-hadrian

canceled #254007
x86_64-linux
validate-x86_64-linux-fedora27

canceled #254009
x86_64-windows allowed to fail
validate-x86_64-windows

canceled #254008
x86_64-windows allowed to fail
validate-x86_64-windows-hadrian

 
  Cleanup
canceled #254010
x86_64-darwin
cleanup-darwin

 
  Packaging
canceled #254011
x86_64-linux allowed to fail
doc-tarball

 
  Testing
canceled #254012
x86_64-linux allowed to fail manual
hackage

canceled #254013
x86_64-linux
perf-nofib

 
  Deploy
canceled #254014
x86_64-linux allowed to fail
pages