Remove `arm32v6`-specific tag

This section of code seems to be breaking the Docker release workflow as of a
few days ago, though it's unclear why. This tag only existed to work around
an issue with Docker pulling the wrong image for ARMv6 platforms; that issue
was resolved in Docker 20.10.0, which has been out for a few years now, so it
seems like a reasonable time to drop this tag.

hooks/push

@@ -108,42 +108,3 @@ docker buildx build \
        "${tag_args[@]}" \
        --push \
        - < ./docker/Dockerfile.buildx
-
-# Add an extra arch-specific tag for `arm32v6`; Docker can't seem to properly
-# auto-select that image on ARMv6 platforms like Raspberry Pi 1 and Zero
-# (https://github.com/moby/moby/issues/41017).
-#
-# Note that we use `arm32v6` instead of `armv6` to be consistent with the
-# existing vaultwarden tags, which adhere to the naming conventions of the
-# Docker per-architecture repos (e.g., https://hub.docker.com/u/arm32v6).
-# Unfortunately, these per-arch repo names aren't always consistent with the
-# corresponding platform (OS/arch/variant) IDs, particularly in the case of
-# 32-bit ARM arches (e.g., `linux/arm/v6` is used, not `linux/arm32/v6`).
-#
-# TODO: It looks like this issue should be fixed starting in Docker 20.10.0,
-# so this step can be removed once fixed versions are in wider distribution.
-#
-# Tags:
-#
-#   testing        => testing-arm32v6
-#   testing-alpine => <ignored>
-#   x.y.z          => x.y.z-arm32v6, latest-arm32v6
-#   x.y.z-alpine   => <ignored>
-#
-if [[ "${DOCKER_TAG}" != *alpine ]]; then
-    image="${DOCKER_REPO}":"${DOCKER_TAG}"
-
-    # Fetch the multi-arch manifest list and find the digest of the armv6 image.
-    filter='.manifests|.[]|select(.platform.architecture=="arm" and .platform.variant=="v6")|.digest'
-    digest="$(docker manifest inspect "${image}" | jq -r "${filter}")"
-
-    # Pull the armv6 image by digest, retag it, and repush it.
-    docker pull "${DOCKER_REPO}"@"${digest}"
-    docker tag "${DOCKER_REPO}"@"${digest}" "${image}"-arm32v6
-    docker push "${image}"-arm32v6
-
-    if [[ "${DOCKER_TAG}" =~ ^[0-9]+\.[0-9]+\.[0-9]+ ]]; then
-        docker tag "${image}"-arm32v6 "${DOCKER_REPO}:latest"-arm32v6
-        docker push "${DOCKER_REPO}:latest"-arm32v6
-    fi
-fi