Stop using build-tools image in compute image build (#12306)

The build-tools image contains various build tools and dependencies,
mostly Rust-related. The compute image build used it to build
compute_ctl and a few other little rust binaries that are included in
the compute image. However, for extensions built in Rust (pgrx), the
build used a different layer which installed the rust toolchain using
rustup.

Switch to using the same rust toolchain for both pgrx-based extensions
and compute_ctl et al. Since we don't need anything else from the
build-tools image, I switched to using the toolchain installed with
rustup, and eliminated the dependency to build-tools altogether. The
compute image build no longer depends on build-tools.

Note: We no longer use 'mold' for linking compute_ctl et al, since mold
is not included in the build-deps-with-cargo layer. We could add it
there, but it doesn't seem worth it. I proposed stopping using mold
altogether in https://github.com/neondatabase/neon/pull/10735, but that
was rejected because 'mold' is faster for incremental builds. That
doesn't matter much for docker builds however, since they're not
incremental, and the compute binaries are not as large as the storage
server binaries anyway.

.github/workflows/build_and_test.yml

@@ -670,7 +670,7 @@ jobs:
                                              ghcr.io/neondatabase/neon:${{ needs.meta.outputs.build-tag }}-bookworm-arm64
 
   compute-node-image-arch:
-    needs: [ check-permissions, build-build-tools-image, meta ]
+    needs: [ check-permissions, meta ]
     if: ${{ contains(fromJSON('["push-main", "pr", "compute-rc-pr"]'), needs.meta.outputs.run-kind) }}
     permissions:
       id-token: write # aws-actions/configure-aws-credentials
@@ -743,7 +743,6 @@ jobs:
             GIT_VERSION=${{ github.event.pull_request.head.sha || github.sha }}
             PG_VERSION=${{ matrix.version.pg }}
             BUILD_TAG=${{ needs.meta.outputs.release-tag || needs.meta.outputs.build-tag }}
-            TAG=${{ needs.build-build-tools-image.outputs.image-tag }}-${{ matrix.version.debian }}
             DEBIAN_VERSION=${{ matrix.version.debian }}
           provenance: false
           push: true
@@ -763,7 +762,6 @@ jobs:
             GIT_VERSION=${{ github.event.pull_request.head.sha || github.sha }}
             PG_VERSION=${{ matrix.version.pg }}
             BUILD_TAG=${{ needs.meta.outputs.release-tag || needs.meta.outputs.build-tag }}
-            TAG=${{ needs.build-build-tools-image.outputs.image-tag }}-${{ matrix.version.debian }}
             DEBIAN_VERSION=${{ matrix.version.debian }}
           provenance: false
           push: true

compute/compute-node.Dockerfile

@@ -77,9 +77,6 @@
 # build_and_test.yml github workflow for how that's done.
 
 ARG PG_VERSION
-ARG REPOSITORY=ghcr.io/neondatabase
-ARG IMAGE=build-tools
-ARG TAG=pinned
 ARG BUILD_TAG
 ARG DEBIAN_VERSION=bookworm
 ARG DEBIAN_FLAVOR=${DEBIAN_VERSION}-slim
@@ -150,6 +147,7 @@ RUN case $DEBIAN_VERSION in \
     zlib1g-dev libxml2-dev libcurl4-openssl-dev libossp-uuid-dev wget ca-certificates pkg-config libssl-dev \
     libicu-dev libxslt1-dev liblz4-dev libzstd-dev zstd curl unzip g++ \
     libclang-dev \
+    jsonnet \
     $VERSION_INSTALLS \
     && apt clean && rm -rf /var/lib/apt/lists/* && \
     useradd -ms /bin/bash nonroot -b /home
@@ -1724,7 +1722,7 @@ FROM extensions-${EXTENSIONS} AS neon-pg-ext-build
 # Compile the Neon-specific `compute_ctl`, `fast_import`, and `local_proxy` binaries
 #
 #########################################################################################
-FROM $REPOSITORY/$IMAGE:$TAG AS compute-tools
+FROM build-deps-with-cargo AS compute-tools
 ARG BUILD_TAG
 ENV BUILD_TAG=$BUILD_TAG
 
@@ -1734,7 +1732,7 @@ COPY --chown=nonroot . .
 RUN --mount=type=cache,uid=1000,target=/home/nonroot/.cargo/registry \
     --mount=type=cache,uid=1000,target=/home/nonroot/.cargo/git \
     --mount=type=cache,uid=1000,target=/home/nonroot/target \
-    mold -run cargo build --locked --profile release-line-debug-size-lto --bin compute_ctl --bin fast_import --bin local_proxy && \
+    cargo build --locked --profile release-line-debug-size-lto --bin compute_ctl --bin fast_import --bin local_proxy && \
     mkdir target-bin && \
     cp target/release-line-debug-size-lto/compute_ctl \
        target/release-line-debug-size-lto/fast_import \
@@ -1828,10 +1826,11 @@ RUN rm /usr/local/pgsql/lib/lib*.a
 # Preprocess the sql_exporter configuration files
 #
 #########################################################################################
-FROM $REPOSITORY/$IMAGE:$TAG AS sql_exporter_preprocessor
+FROM build-deps AS sql_exporter_preprocessor
 ARG PG_VERSION
 
 USER nonroot
+WORKDIR /home/nonroot
 
 COPY --chown=nonroot compute compute