fix: add git to containers to support provenance (#170)

Author: xoxys

docker/Dockerfile.amd64

@@ -15,6 +15,7 @@ ENV BUILDX_VERSION="${BUILDX_VERSION:-v0.10.0}"
 ENV DOCKER_HOST=unix:///var/run/docker.sock
 
 RUN apk --update add --virtual .build-deps curl && \
+    apk --update add --no-cache git && \
     mkdir -p /usr/lib/docker/cli-plugins/ && \
     curl -SsL -o /usr/lib/docker/cli-plugins/docker-buildx "https://github.com/docker/buildx/releases/download/v${BUILDX_VERSION##v}/buildx-v${BUILDX_VERSION##v}.linux-amd64" && \
     chmod 755 /usr/lib/docker/cli-plugins/docker-buildx && \

docker/Dockerfile.arm64

@@ -15,6 +15,7 @@ ENV BUILDX_VERSION="${BUILDX_VERSION:-v0.10.0}"
 ENV DOCKER_HOST=unix:///var/run/docker.sock
 
 RUN apk --update add --virtual .build-deps curl && \
+    apk --update add --no-cache git && \
     mkdir -p /usr/lib/docker/cli-plugins/ && \
     curl -SsL -o /usr/lib/docker/cli-plugins/docker-buildx "https://github.com/docker/buildx/releases/download/v${BUILDX_VERSION##v}/buildx-v${BUILDX_VERSION##v}.linux-arm64" && \
     chmod 755 /usr/lib/docker/cli-plugins/docker-buildx && \