perf: removed duplicated dockerfile deps to speed up the build

.dockerignore

@@ -0,0 +1,4 @@
+**
+!Dockerfile
+!scripts/
+!scripts/build-sqlite3-wasm.sh

Dockerfile

@@ -1,36 +1,22 @@
 # syntax=docker/dockerfile:1
 ARG EMSDK_VERSION=5.0.5
-FROM emscripten/emsdk:${EMSDK_VERSION}
-
-ARG DEBIAN_FRONTEND=noninteractive
+FROM emscripten/emsdk:${EMSDK_VERSION} AS wasm-tools
 
-# runtime / build deps
-RUN apt-get update \
- && apt-get install -y --no-install-recommends \
-    ca-certificates \
-    git \
-    build-essential \
-    autoconf \
-    automake \
-    libtool \
-    m4 \
-    python3 \
-    nodejs \
-    npm \
-    zip \
-    unzip \
-    curl \
-    wabt \
- && rm -rf /var/lib/apt/lists/*
+# The SDK already supplies the build dependencies. SQLite's release build
+# only needs wasm-strip from WABT; install the package in a helper stage.
+RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
+    --mount=type=cache,target=/var/lib/apt/lists,sharing=locked \
+    rm -f /etc/apt/apt.conf.d/docker-clean \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends wabt
 
-# create useful dirs
-RUN mkdir -p /build /out /src/bin /work
+FROM emscripten/emsdk:${EMSDK_VERSION}
 
-# copy helper script
-COPY scripts/build-sqlite3-wasm.sh /usr/local/bin/build-sqlite3-wasm.sh
-RUN chmod +x /usr/local/bin/build-sqlite3-wasm.sh
+# Using the same SDK base in both stages preserves binary compatibility.
+COPY --from=wasm-tools /usr/bin/wasm-strip /usr/local/bin/wasm-strip
+COPY --from=wasm-tools /usr/share/doc/wabt/copyright /usr/share/doc/wabt/copyright
 
-WORKDIR /work
+COPY --chmod=755 scripts/build-sqlite3-wasm.sh /usr/local/bin/build-sqlite3-wasm.sh
 
 ENTRYPOINT ["/usr/local/bin/build-sqlite3-wasm.sh"]
 CMD ["build"]