Replace unzip with bsdtar

There are situations where a Zip archive from Sourcegraph causes the
directory to be improperly recreated within the container. Using
libarchive-tools fixes this.

Author: lowjoel

docker/batch-change-volume-workspace/Dockerfile

@@ -4,4 +4,4 @@
 
 FROM alpine:3.15.0@sha256:21a3deaa0d32a8057914f36584b5288d2e5ecc984380bc0118285c70fa8c9300
 
-RUN apk add --update git unzip
+RUN apk add --update git libarchive-tools

internal/batches/workspace/volume_workspace.go

@@ -153,7 +153,7 @@ func (wc *dockerVolumeWorkspaceCreator) unzipRepoIntoVolume(ctx context.Context,
 		opts,
 		DockerVolumeWorkspaceImage,
 		"sh", "-c",
-		fmt.Sprintf("unzip /tmp/zip; rm /work/%s", dummy),
+		fmt.Sprintf("bsdtar -xf /tmp/zip && rm /work/%s", dummy),
 	)
 
 	if out, err := exec.CommandContext(ctx, "docker", opts...).CombinedOutput(); err != nil {