build(deps): update alpine docker tag to v3.18

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Dockerfile

@@ -33,7 +33,7 @@ RUN GOOS=linux go build -ldflags '-linkmode=external' -gcflags="${SKAFFOLD_GO_GC
 
 # Use a Docker multi-stage build to create a lean production image.
 # https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
-FROM alpine:3.16
+FROM alpine:3.18
 # Install extra packages
 # See https://github.com/gliderlabs/docker-alpine/issues/136#issuecomment-272703023