Allow overriding the assembly location, to fix computation of RootLocation when running tests.
#jira none
#ROBOMERGE-SOURCE: CL 16658527 in //UE5/Main/...
#ROBOMERGE-BOT: STARSHIP (Main -> Release-Engine-Test) (v833-16641396)
[CL 16658543 by jonathan adamczewski in ue5-release-engine-test branch]
Fix after refactorings of UnrealBuildTool/BuildUtilities.
#jira none
#trivial
#ROBOMERGE-SOURCE: CL 16628761 in //UE5/Main/...
#ROBOMERGE-BOT: STARSHIP (Main -> Release-Engine-Test) (v831-16623017)
[CL 16628767 by jonathan adamczewski in ue5-release-engine-test branch]