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] <[email protected]>

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.18.3 AS builder
+FROM alpine:3.18.4 AS builder
 ENV MERGERFS_VERSION=2.37.1
 
 RUN apk add g++ git linux-headers make python3
@@ -9,7 +9,7 @@ RUN git checkout -b $MERGERFS_VERSION
 RUN make
 RUN mv build/mergerfs /bin/mergerfs
 
-FROM alpine:3.18.3
+FROM alpine:3.18.4
 COPY --from=builder /bin/mergerfs /usr/local/bin/mergerfs
 
 RUN apk --no-cache add fuse libgcc libstdc++