policy-controller: Do not use caching
crazy-max/ghaction-docker-buildx#172 describes a problem with
cross-building docker images--especially 32b ARM images--and docker
caching.
This change removes caching from the policy-controller dockerfile to
avoid this issue.
@@ -6,9 +6,7 @@ FROM $RUST_IMAGE as build
ARG TARGETARCH
WORKDIR /build
COPY . /build
-RUN --mount=type=cache,target=target \
- --mount=type=cache,from=rust:1.54.0-buster,source=/usr/local/cargo,target=/usr/local/cargo \
- target=$(rustup show | sed -n 's/^Default host: \(.*\)/\1/p') ; \
+RUN target=$(rustup show | sed -n 's/^Default host: \(.*\)/\1/p') ; \
cargo build --locked --release --target="$target" --package=linkerd-policy-controller && \
mv "target/${target}/release/linkerd-policy-controller" /tmp/
