chore(deps): update alpine docker tag to v3.18.4 (main) (grafana#11167)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| alpine | final | patch | `3.18.3` -> `3.18.4` |
| alpine | final | minor | `3.16.7` -> `3.18.4` |

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production/helm/loki/src/helm-test/Dockerfile

@@ -7,7 +7,7 @@ COPY . /src/loki
 WORKDIR /src/loki
 RUN make clean && make BUILD_IN_CONTAINER=false helm-test
 
-FROM alpine:3.16.7
+FROM alpine:3.18.4
 RUN apk add --update --no-cache ca-certificates=20230506-r0
 COPY --from=build /src/loki/production/helm/loki/src/helm-test/helm-test /usr/bin/helm-test
 ENTRYPOINT [ "/usr/bin/helm-test" ]