READY Update simnet tests to v5 (#8946)

* Update simnet tests to v4

* enable simnet tests for PRs

* add stage to job "test-linux-stable-int"

* v2.0.0simnet

* alow build-for-simnet option

* Fix passing of IMAGE_TAG to downstream

* forgot to build-for-simnet

* build-for-simnet

* build-for-simnet

* build-for-simnet

* build-for-simnet

* build-for-simnet

* take a shortcut build-for-simnet

* build-for-simnet

* update triggering script to polkadot version

* "revert me"

* "revert me"  build-for-simnet

* add simnet version as arg to script

* revert me build-for-simnet

* build-for-simnet

* remove triggering simnet for PRs for now

* Add suggestions from Vladimir

* Add suggestions from Vladimir