Docker: Build ARM image natively (#7046)

* native builds + merge

* naming and ordering

* use ninja and cmake build

* add ccache and cache mounts

* formatting

* Update servatrice.cpp

* Revert "Update servatrice.cpp"

This reverts commit 3acc684135c6db9baa17d00deaceecf8f7079721.

* remove ccache again

cache mounts are not part of GHA caches from docker action

* comments and cleanup

Use buildx provided in runner, see https://github.com/actions/runner-images/blob/main/images/ubuntu-slim/ubuntu-slim-Readme.md

* more explicit

* comments, first pass

* ${{ runner.temp }}

* $(printf "$GHCR_IMAGE@sha256:%s " *)

* follow docker docs for latest and extract short semver from our tags

* not so pretty, but allows the easy inspect at the end

* add Servatrice name

* add links to runner images

* comments, second pass

* cleanup

Dockerfile

@@ -3,35 +3,45 @@ FROM ubuntu:26.04 AS build
 
 ARG DEBIAN_FRONTEND=noninteractive
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
-  build-essential \
-  cmake \
-  file \
-  g++ \
-  git \
-  libmariadb-dev-compat \
-  libprotobuf-dev \
-  libqt6sql6-mysql \
-  qt6-websockets-dev \
-  protobuf-compiler \
-  qt6-tools-dev \
-  qt6-tools-dev-tools
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+      build-essential \
+      cmake \
+      ninja-build \
+      file \
+      g++ \
+      git \
+      libmariadb-dev-compat \
+      libprotobuf-dev \
+      libqt6sql6-mysql \
+      qt6-websockets-dev \
+      protobuf-compiler \
+      qt6-tools-dev \
+      qt6-tools-dev-tools
 
 WORKDIR /src
 COPY . .
-RUN mkdir build && cd build && \
-    cmake .. -DWITH_SERVER=1 -DWITH_CLIENT=0 -DWITH_ORACLE=0 && \
-    make -j$(nproc) && \
-    make install
+RUN cmake \
+      -S . \
+      -B build \
+      -G Ninja \
+      -DWITH_CLIENT=0 \
+      -DWITH_ORACLE=0 \
+      -DWITH_SERVER=1 \
+    && cmake --build build \
+    && cmake --install build
 
 
 # -------- Runtime Stage (clean) --------
 FROM ubuntu:26.04
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
-  libprotobuf32t64 \
-  libqt6sql6-mysql \
-  libqt6websockets6 \
+ARG DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+      libprotobuf32t64 \
+      libqt6sql6-mysql \
+      libqt6websockets6 \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*