Downgrading mysqld-exporter version

Lower the version of the mysqld-exporter, which is the latest
buildable with go 1.21

Author: vyzigold

config/operator/default_images.yaml

@@ -40,7 +40,7 @@ spec:
         - name: RELATED_IMAGE_CEILOMETER_NOTIFICATION_IMAGE_URL_DEFAULT
           value: quay.io/podified-antelope-centos9/openstack-ceilometer-notification:current-podified
         - name: RELATED_IMAGE_CEILOMETER_MYSQLD_EXPORTER_IMAGE_URL_DEFAULT
-          value: quay.io/prometheus/mysqld-exporter:v0.16.0
+          value: quay.io/prometheus/mysqld-exporter:v0.15.1
         - name: RELATED_IMAGE_CEILOMETER_SGCORE_IMAGE_URL_DEFAULT
           value: quay.io/openstack-k8s-operators/sg-core:latest
         - name: RELATED_IMAGE_KSM_IMAGE_URL_DEFAULT

hack/export_related_images.sh

@@ -34,7 +34,7 @@ export RELATED_IMAGE_CEILOMETER_COMPUTE_IMAGE_URL_DEFAULT=quay.io/podified-antel
 export RELATED_IMAGE_CEILOMETER_NOTIFICATION_IMAGE_URL_DEFAULT=quay.io/podified-antelope-centos9/openstack-ceilometer-notification:current-podified
 export RELATED_IMAGE_CEILOMETER_IPMI_IMAGE_URL_DEFAULT=quay.io/podified-antelope-centos9/openstack-ceilometer-ipmi:current-podified
 export RELATED_IMAGE_CEILOMETER_SGCORE_IMAGE_URL_DEFAULT=quay.io/openstack-k8s-operators/sg-core:latest
-export RELATED_IMAGE_CEILOMETER_MYSQLD_EXPORTER_IMAGE_URL_DEFAULT=quay.io/prometheus/mysqld-exporter:v0.16.0
+export RELATED_IMAGE_CEILOMETER_MYSQLD_EXPORTER_IMAGE_URL_DEFAULT=quay.io/prometheus/mysqld-exporter:v0.15.1
 export RELATED_IMAGE_KSM_IMAGE_URL_DEFAULT=registry.k8s.io/kube-state-metrics/kube-state-metrics:v2.15.0
 export RELATED_IMAGE_AODH_API_IMAGE_URL_DEFAULT=quay.io/podified-antelope-centos9/openstack-aodh-api:current-podified
 export RELATED_IMAGE_AODH_EVALUATOR_IMAGE_URL_DEFAULT=quay.io/podified-antelope-centos9/openstack-aodh-evaluator:current-podified