[bazel] bitstreams don't refresh when offline

and added latest.txt

Signed-off-by: Drew Macrae <drewmacrae@google.com>
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index e2909df..d419033 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -446,7 +446,9 @@
       BITCACHE_FILE=$BITCACHE_DIR/lowrisc_systems_chip_earlgrey_cw310_0.1.bit.orig
       cp $BIN_DIR/hw/top_earlgrey/lowrisc_systems_chip_earlgrey_cw310_0.1.bit ${BITCACHE_FILE}
       echo "" >> ${BITCACHE_DIR}/lowrisc_systems_chip_earlgrey_cw310_0.1.bit.splice
-      BITSTREAM="--offline --list ${SHA}" ci/bazelisk.sh test \
+      echo -n ${SHA} > ${BITCACHE_DIR}/../../latest.txt
+      export BITSTREAM="--offline --list ${SHA}"
+      ci/bazelisk.sh test \
           --define DISABLE_VERILATOR_BUILD=true \
           --test_tag_filters=cw310,-broken \
           --test_output=all \