Add workaround for clamav base image problem

.github/workflows/build_and_push.yml

@@ -40,6 +40,18 @@ jobs:
           repository: docker-mailserver/docker-mailserver
           submodules: recursive
           ref: ${{ matrix.version }}
+      - name: Check out fixes required for docker build
+        uses: actions/checkout@v4
+        with:
+          sparse-checkout: |
+            clamav-base-image.patch
+          sparse-checkout-cone-mode: false
+          path: patch_files
+      - name: Apply fixes required for docker build
+        shell: bash
+        run: |
+          patch -p1 -f --no-backup-if-mismatch < patch_files/clamav-base-image.patch
+          rm -f clamav-base-image.patch
       - name: Determine required variable values
         id: vars
         shell: bash

clamav-base-image.patch

@@ -0,0 +1,13 @@
+diff --git a/Dockerfile b/Dockerfile
+index 09295a22..f2e48bdd 100644
+--- a/Dockerfile
++++ b/Dockerfile
+@@ -62,7 +62,7 @@ SHELL ["/bin/bash", "-e", "-o", "pipefail", "-c"]
+ # which would require an extra memory of 500MB+ during an image build.
+ # When using `COPY --link`, the `--chown` option is only compatible with numeric ID values.
+ # hadolint ignore=DL3021
+-COPY --link --chown=200 --from=docker.io/clamav/clamav:latest /var/lib/clamav /var/lib/clamav
++COPY --link --chown=200 --from=docker.io/clamav/clamav-debian:latest /var/lib/clamav /var/lib/clamav
+
+ RUN <<EOF
+   # `COPY --link --chown=200` has a bug when built by the buildx docker-container driver.