Always use the alternate repo for arm32

builds.expected

@@ -2405,7 +2405,7 @@ debian-11/ppc64le
 debian-11/arm32v7
 	# syntax=docker/dockerfile:1
 	# Autogenerated by OCaml-Dockerfile scripts
-	FROM --platform=arm debian:11
+	FROM --platform=arm arm32v7/debian:11
 	SHELL [ "/usr/bin/linux32", "/bin/bash", "-c" ]
 	LABEL distro_style="apt"
 	RUN apt-get -y update
@@ -2417,7 +2417,7 @@ debian-11/arm32v7
 	RUN cd /tmp/opam-sources && cp -P -R -p . ../opam-build-2.0 && cd ../opam-build-2.0 && git checkout 2.0 && ln -s ../opam/src_ext/archives src_ext/archives && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" ./configure --enable-cold-check && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" make lib-ext all && mkdir -p /usr/local/bin && cp /tmp/opam-build-2.0/opam /usr/local/bin/opam-2.0 && chmod a+x /usr/local/bin/opam-2.0 && rm -rf /tmp/opam-build-2.0
 	RUN cd /tmp/opam-sources && cp -P -R -p . ../opam-build-2.1 && cd ../opam-build-2.1 && git checkout 2.1 && ln -s ../opam/src_ext/archives src_ext/archives && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" ./configure --enable-cold-check --with-0install-solver && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" make lib-ext all && mkdir -p /usr/local/bin && cp /tmp/opam-build-2.1/opam /usr/local/bin/opam-2.1 && chmod a+x /usr/local/bin/opam-2.1 && rm -rf /tmp/opam-build-2.1
 	RUN cd /tmp/opam-sources && cp -P -R -p . ../opam-build-master && cd ../opam-build-master && git checkout master && ln -s ../opam/src_ext/archives src_ext/archives && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" ./configure --enable-cold-check --with-0install-solver && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" make lib-ext all && mkdir -p /usr/local/bin && cp /tmp/opam-build-master/opam /usr/local/bin/opam-master && chmod a+x /usr/local/bin/opam-master && rm -rf /tmp/opam-build-master
-	FROM debian:11
+	FROM arm32v7/debian:11
 	RUN ln -fs /usr/share/zoneinfo/Europe/London /etc/localtime
 	RUN apt-get -y update
 	RUN DEBIAN_FRONTEND=noninteractive apt-get -y upgrade
@@ -6055,7 +6055,7 @@ debian-10/ppc64le
 debian-10/arm32v7
 	# syntax=docker/dockerfile:1
 	# Autogenerated by OCaml-Dockerfile scripts
-	FROM --platform=arm debian:10
+	FROM --platform=arm arm32v7/debian:10
 	SHELL [ "/usr/bin/linux32", "/bin/bash", "-c" ]
 	LABEL distro_style="apt"
 	RUN apt-get -y update
@@ -6071,7 +6071,7 @@ debian-10/arm32v7
 	RUN cd /tmp/opam-sources && cp -P -R -p . ../opam-build-2.0 && cd ../opam-build-2.0 && git checkout 2.0 && ln -s ../opam/src_ext/archives src_ext/archives && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" ./configure --enable-cold-check && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" make lib-ext all && mkdir -p /usr/local/bin && cp /tmp/opam-build-2.0/opam /usr/local/bin/opam-2.0 && chmod a+x /usr/local/bin/opam-2.0 && rm -rf /tmp/opam-build-2.0
 	RUN cd /tmp/opam-sources && cp -P -R -p . ../opam-build-2.1 && cd ../opam-build-2.1 && git checkout 2.1 && ln -s ../opam/src_ext/archives src_ext/archives && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" ./configure --enable-cold-check --with-0install-solver && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" make lib-ext all && mkdir -p /usr/local/bin && cp /tmp/opam-build-2.1/opam /usr/local/bin/opam-2.1 && chmod a+x /usr/local/bin/opam-2.1 && rm -rf /tmp/opam-build-2.1
 	RUN cd /tmp/opam-sources && cp -P -R -p . ../opam-build-master && cd ../opam-build-master && git checkout master && ln -s ../opam/src_ext/archives src_ext/archives && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" ./configure --enable-cold-check --with-0install-solver && env PATH="/tmp/opam/bootstrap/ocaml/bin:$PATH" make lib-ext all && mkdir -p /usr/local/bin && cp /tmp/opam-build-master/opam /usr/local/bin/opam-master && chmod a+x /usr/local/bin/opam-master && rm -rf /tmp/opam-build-master
-	FROM debian:10
+	FROM arm32v7/debian:10
 	RUN ln -fs /usr/share/zoneinfo/Europe/London /etc/localtime
 	COPY --from=0 [ "/usr/local/bin/bwrap", "/usr/bin/bwrap" ]
 	RUN apt-get -y update