build: disable provenance attestations in container builds (#523)

## Summary
- Add `--provenance=false` to docker build commands in
`build-container.sh`
- BuildKit attestation manifests are stored as untagged images in GHCR,
and the `delete-untagged-containers` cleanup job deletes them, breaking
the manifest list and causing `manifest unknown` errors on pull
- ref: https://github.com/actions/delete-package-versions/issues/162

docker/build-container.sh

@@ -142,7 +142,7 @@ for CONTAINER_TYPE in non-root root; do
   fi
 
   log_info "Building $CONTAINER_TYPE $CONTAINER_TAG $LS_VER"
-  docker build -f llama-swap.Containerfile --build-arg BASE_TAG=${BASE_TAG} --build-arg LS_VER=${LS_VER} --build-arg UID=${USER_UID} \
+  docker build --provenance=false -f llama-swap.Containerfile --build-arg BASE_TAG=${BASE_TAG} --build-arg LS_VER=${LS_VER} --build-arg UID=${USER_UID} \
     --build-arg LS_REPO=${LS_REPO} --build-arg GID=${USER_GID} --build-arg USER_HOME=${USER_HOME} -t ${CONTAINER_TAG} -t ${CONTAINER_LATEST} \
     --build-arg BASE_IMAGE=${BASE_IMAGE} .
 
@@ -150,7 +150,7 @@ for CONTAINER_TYPE in non-root root; do
   case "$ARCH" in
     "musa" | "vulkan")
       log_info "Adding sd-server to $CONTAINER_TAG"
-      docker build -f llama-swap-sd.Containerfile \
+      docker build --provenance=false -f llama-swap-sd.Containerfile \
         --build-arg BASE=${CONTAINER_TAG} \
         --build-arg SD_IMAGE=${SD_IMAGE} --build-arg SD_TAG=${SD_TAG} \
         --build-arg UID=${USER_UID} --build-arg GID=${USER_GID} \