Update alpine Docker tag to v3.18.5

Dockerfile

@@ -13,7 +13,7 @@ RUN go mod download \
   && go build -v ./cmd/transmission-exporter
 
 # 2. stage
-FROM alpine:3.18.4
+FROM alpine:3.18.5
 COPY --from=build /app/transmission-exporter /usr/bin/transmission-exporter
 # COPY --chmod=755 .. requires Buildkit
 RUN chmod 755 /usr/bin/transmission-exporter \