docker-rotate-sa(deps): bump alpine

Bumps alpine from 3.18.4 to 3.18.5.

---
updated-dependencies:
- dependency-name: alpine
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

cmd/cloud-run/rotate-service-account/Dockerfile

@@ -5,7 +5,7 @@ COPY . .
 
 RUN  CGO_ENABLED=0 go build -o /rotateserviceaccount -ldflags="-s -w" ./cmd/cloud-run/rotate-service-account
 
-FROM alpine:3.18.4
+FROM alpine:3.18.5
 
 COPY --from=builder /rotateserviceaccount /rotateserviceaccount
 RUN apk add --no-cache ca-certificates && \