ci: forward the TOOLSTATE_PUBLISH environment variable inside docker

A recent commit modified toolstate to only push updated data when the
TOOLSTATE_PUBLISH environment variable is present. This worked fine on
Windows but failed on Linux, since Linux jobs run inside Docker
containers and the variable wasn't forwarded inside it.

This changes the Docker startup code to set the TOOLSTATE_PUBLISH
enviornment variable inside the container if it's present outside.

Author: pietroalbini

src/ci/docker/run.sh

@@ -172,6 +172,7 @@ docker \
   --env BUILD_SOURCEBRANCHNAME \
   --env TOOLSTATE_REPO_ACCESS_TOKEN \
   --env TOOLSTATE_REPO \
+  --env TOOLSTATE_PUBLISH \
   --env CI_JOB_NAME="${CI_JOB_NAME-$IMAGE}" \
   --init \
   --rm \