cirrus: run make with parallel jobs where useful

The doc generation and the validate-binaries target can be run in
parallel as they do not depend on each other and a specific ordering. As
such we pass -j $(nproc) but also --output-sync=target to ensure the
output is not intermixed between several targets which could be harder
to read in case of errors.

Hower dus the complex podman-release target we can run podman-release
and validate-binaries at the same time as the dependencies are not right
and we run podman-release first in order to get the correct binaires
build.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

contrib/cirrus/runner.sh

@@ -210,19 +210,17 @@ eof
 }
 
 function _run_build() {
-    local vb_target
+    # Ensure always start from clean-slate with all vendor modules downloaded
+    showrun make clean
+    showrun make vendor
+    showrun make -j $(nproc) --output-sync=target podman-release  # includes podman, podman-remote, and docs
 
     # There's no reason to validate-binaries across multiple linux platforms
     # shellcheck disable=SC2154
     if [[ "$DISTRO_NV" =~ $FEDORA_NAME ]]; then
-        vb_target=validate-binaries
+        showrun make -j $(nproc) --output-sync=target validate-binaries
     fi
 
-    # Ensure always start from clean-slate with all vendor modules downloaded
-    showrun make clean
-    showrun make vendor
-    showrun make podman-release $vb_target # includes podman, podman-remote, and docs
-
     # Last-minute confirmation that we're testing the desired runtime.
     # This Can't Possibly Fail™ in regular CI; only when updating VMs.
     # $CI_DESIRED_RUNTIME must be defined in .cirrus.yml.