Update Dockerfile (bump Hugo to 0.139.3)

Dockerfiles/Dockerfile

@@ -1,7 +1,7 @@
 # Use alpine Linux, download desired version of HUGO and build html files
 FROM alpine:3.19.1 AS build
 RUN apk add --no-cache wget=1.21.4-r0
-ARG HUGO_VERSION="0.123.7"
+ARG HUGO_VERSION="0.139.3"
 ARG HUGO_ENV_ARG
 WORKDIR /src
 COPY ./ /src