[TASK] Fix docker image issue with tangle node for CI tests

[salman01zp]

Overview

Some of the CI tests with tangle as backend fail with the following error

2023-09-22 16:37:34          API-WS: disconnected from ws://127.0.0.1:9945: 1006:: Abnormal Closure
docker network create --subnet=172.20.0.0/16 tangle exited with code 1
Relayer 40969 exited with code: 0

for more details: https://github.com/webb-tools/relayer/actions/runs/6276687793/job/17046917086#step:10:109

[shekohex]

Mostly the issue related to create a docker custom subnet, it is useful so that tangle nodes sees each others.