chore: bump alpine from 3.18.3 to 3.18.4

Bumps alpine from 3.18.3 to 3.18.4.

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

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

Dockerfile

@@ -13,7 +13,7 @@ ENV GOOS=$TARGETOS
 ENV GOARCH=$TARGETARCH
 RUN go build -ldflags="-X '$PACKAGE/shared.Version=$VERSION' -X '$PACKAGE/shared.Hash=$HASH'" -o raker ./server
 
-FROM --platform=$BUILDPLATFORM alpine:3.18.3 AS server
+FROM --platform=$BUILDPLATFORM alpine:3.18.4 AS server
 WORKDIR /raker
 COPY --from=build /raker/raker .
 COPY templates templates