[ci] build runtime only if runtime files were changed (#1582)

* [WIP][ci] build runtime only if runtime files were changed

* debug

* enable valid job

* enable valid job

* enable everything back

* test build-runtime-assets-statemine

* add need

* build nightly

* test build runtime statemint

* cargo check instead build

* rm test file

* restart pipeline

* add paths to build-runtime-template

* add test file to trigger builds

* move test

* remove test file

* trigger pipeline to calculate times

* modify build-runtime jobs

* add echo

* fix semicolon

* debug

* fix variable

* uncomment all

* add DAG for build-runtime jobs

* restart pipeline