Add consistent Dockerfile syntax versioning

Dockerfile

@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.2
+# syntax=docker/dockerfile:1
 FROM alpine:3.24
 
 RUN apk add --no-cache --no-progress ca-certificates tzdata

docs/check.Dockerfile

@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 FROM alpine:3.24
 
 RUN apk --no-cache --no-progress add \

docs/docs.Dockerfile

@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 FROM alpine:3.24
 
 ENV PATH="${PATH}:/venv/bin"

webui/Dockerfile

@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 FROM node:24-alpine3.24
 # Current Active LTS release according to (https://nodejs.org/en/about/releases/)