ci: run RISC-V cross jobs by default

The riscv64-debian-cross container is based on Trixie rather than sid
these days, so it is pretty much as stable as the others.  Enable it
by default.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

.gitlab-ci.d/container-cross.yml

@@ -67,11 +67,8 @@ ppc64el-debian-cross-container:
 riscv64-debian-cross-container:
   extends: .container_job_template
   stage: containers
-  # as we are currently based on 'sid/unstable' we may break so...
-  allow_failure: true
   variables:
     NAME: debian-riscv64-cross
-    QEMU_JOB_OPTIONAL: 1
 
 s390x-debian-cross-container:
   extends: .container_job_template

.gitlab-ci.d/crossbuilds.yml

@@ -118,12 +118,8 @@ cross-ppc64el-kvm-only:
     IMAGE: debian-ppc64el-cross
     EXTRA_CONFIGURE_OPTS: --disable-tcg --without-default-devices
 
-# The riscv64 cross-builds currently use a 'sid' container to get
-# compilers and libraries. Until something more stable is found we
-# allow_failure so as not to block CI.
 cross-riscv64-system:
   extends: .cross_system_build_job
-  allow_failure: true
   needs:
     job: riscv64-debian-cross-container
   variables:
@@ -131,7 +127,6 @@ cross-riscv64-system:
 
 cross-riscv64-user:
   extends: .cross_user_build_job
-  allow_failure: true
   needs:
     job: riscv64-debian-cross-container
   variables: