Cirrus: Detailed CPU/Memory/Time runner.sh stats

On several occasions, there have been questions about CPU/Memory/IO
trends in testing over time. Start collecting this data for all jobs,
using a common/stable format so that trending analysis can be performed
within/across multiple Cirrus-CI builds. This PR doesn't add any related
tooling, it simply arranges for the collection of the data.

Stats generation is done at the orchestration level to guarantee they
reflect everything happening inside `runner.sh`.  For example, the
container-based tests re-exec `runner.sh` inside a container, but
we're only interested in the top-level stats.

Update all tasks to include collection of the stats file.
Unfortunately, due to the way the Cirrus-CI YAML parser works,
it is *not* possible to alias the artifacts collection more clearly,
for example:

```yaml
    always:
        <<: *runner_stats
        <<: *logs_artifacts
```

Signed-off-by: Chris Evich <cevich@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/contrib/cirrus/runner.sh b/contrib/cirrus/runner.sh
index 084b196a9..1d05dfa71 100755
--- a/contrib/cirrus/runner.sh
+++ b/contrib/cirrus/runner.sh
@@ -253,6 +253,16 @@ dotest() {
         |& logformatter
 }
 
+# Nearly every task in .cirrus.yml makes use of this shell script
+# wrapped by /usr/bin/time to collect runtime statistics.  Because the
+# --output option is used to log stats to a file, every child-process
+# inherits an open FD3 pointing at the log.  However, some testing
+# operations depend on making use of FD3, and so it must be explicitly
+# closed here (and for all further child-processes).
+# STATS_LOGFILE assumed empty/undefined outside of Cirrus-CI (.cirrus.yml)
+# shellcheck disable=SC2154
+exec 3<&-
+
 msg "************************************************************"
 # Required to be defined by caller
 # shellcheck disable=SC2154