JENKINS-65315: SubmoduleOption: resolve env vars in reference path #1556
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JENKINS-65315 - Resolve environment variables in SubmoduleOption reference path
On contrary to Freestyle projects' getEnvironment, WorkflowRun.getEnvironment doesn't provide node-specific environment variables as it can have multiple node blocks in parallel. So I suggest to pick up envvars just in place.
See also #575 where this had already been done for CloneOption
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