[VMR] Publish scenario test results only when available

[akoeplinger]

#40860 wasn't enough, there are more cases when scenario tests are skipped:

sdk/src/SourceBuild/content/test/tests.proj

Lines 6 to 17 in 85b4f73

	<!-- Skip scenario tests if the host architecture is different from the target architecture since the tests
	require the ability to execute the built SDK. But the CLI is not capable of running on a host with a
	different architecture (i.e. "cannot execute binary file: Exec format error"). -->
	<_RunScenarioTests Condition="'$(BuildArchitecture.ToLowerInvariant())' != '$(TargetArchitecture.ToLowerInvariant())'">false</_RunScenarioTests>
	<!-- Skip scenario tests if the portable OS (determined from the host machine) is different from the target OS
	since the tests require the ability to execute the built SDK. An example of where this would be disabled is
	cross-build of using Mariner to build for Alpine (linux vs linux-musl). -->
	<_RunScenarioTests Condition="'$(BuildOS)' != 'windows' and '$(DotNetBuildSourceOnly)' != 'true' and '$(__PortableTargetOS.ToLowerInvariant())' != '$(TargetOS.ToLowerInvariant())'">false</_RunScenarioTests>
	<!-- The scenario tests are not supported when unofficial build versioning is used. -->
	<_RunScenarioTests Condition="'$(UseOfficialBuildVersioning)' == 'false'">false</_RunScenarioTests>

Check whether we have artifacts and set an AzDO variable instead.