chore(deps): update registry.suse.com/bci/bci-base docker tag to v15.7

Author: renovate-rancher[bot]

package/Dockerfile

@@ -17,9 +17,9 @@ RUN make
 #
 # base image
 FROM registry.suse.com/bci/bci-micro:15.6 AS micro
-FROM registry.suse.com/bci/bci-base:15.6 AS base
+FROM registry.suse.com/bci/bci-base:15.7 AS base
 FROM --platform=$BUILDPLATFORM rancher/mirrored-tonistiigi-xx:1.5.0 AS xx
-FROM --platform=$BUILDPLATFORM registry.suse.com/bci/bci-base:15.6 AS basebuilder
+FROM --platform=$BUILDPLATFORM registry.suse.com/bci/bci-base:15.7 AS basebuilder
 
 ARG TARGETPLATFORM
 ARG TARGETOS