CI: Upgrade the build Docker image (#27337)

* CI: Upgrade the build Docker image

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* CI: Upgrade osxcross and Apple SDK

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

scripts/build/ci-build/Dockerfile

@@ -1,11 +1,12 @@
 # Use old Debian (this has support into 2022) in order to ensure binary compatibility with older glibc's.
 FROM debian:stretch-20200803-slim AS toolchain
 
-ENV OSX_SDK_URL=https://s3.dockerproject.org/darwin/v2 \
-    OSX_SDK=MacOSX10.10.sdk \
-    OSX_MIN=10.10 \
+ARG OSX_SDK_URL
+
+ENV OSX_MIN=10.10 \
     CTNG=1.24.0 \
-    OSX_CROSS_REV=542acc2ef6c21aeb3f109c03748b1015a71fed63
+    # This is the last revision that builds on Debian Stretch
+    OSX_CROSS_REV=a1d7d7a8d569f9f0b8c3140b8b32848dbcd62afa
 
 # Use ARG so as not to persist environment variable in image
 ARG DEBIAN_FRONTEND=noninteractive
@@ -37,6 +38,7 @@ WORKDIR /tmp
 RUN apt-get update && \
     apt-get install -yq \
         clang patch libxml2-dev \
+        build-essential \
         ca-certificates \
         curl            \
         git             \
@@ -47,10 +49,10 @@ RUN apt-get update && \
         lzma-dev
 RUN git clone https://github.com/tpoechtrager/osxcross.git /tmp/osxcross && \
       cd /tmp/osxcross && git reset --hard $OSX_CROSS_REV
-RUN curl -fL ${OSX_SDK_URL}/${OSX_SDK}.tar.xz -o /tmp/osxcross/tarballs/${OSX_SDK}.tar.xz
+RUN curl -fL "${OSX_SDK_URL}" -o /tmp/osxcross/tarballs/$(echo "${OSX_SDK_URL}" | grep -E 'MacOSX[^?]+' -o)
 RUN ln -s /usr/bin/llvm-dsymutil-6.0 /usr/bin/dsymutil
-RUN UNATTENDED=yes OSX_VERSION_MIN=${OSX_MIN} /tmp/osxcross/build.sh
-RUN rm -rf /tmp/osxcross/target/SDK/${OSX_SDK}/usr/share && \
+RUN UNATTENDED=1 OSX_VERSION_MIN=${OSX_MIN} /tmp/osxcross/build.sh
+RUN rm -rf /tmp/osxcross/target/SDK/*/usr/share && \
     cd /tmp                                              && \
     tar cfJ osxcross.tar.xz osxcross/target              && \
     rm -rf /tmp/osxcross