[PERF] Use the major version for the net_.0 version in create mono dotnet step

[LoopedBard3]

Use the major version from the Versions.props for the net_.0 version in create mono dotnet. This is recently broken due to the Major version update to 9 while we have 8 hardcoded.

Test run: https://dev.azure.com/dnceng/internal/_build/results?buildId=2257981&view=results

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Issue Details

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Use the major version from the Versions.props for the net_.0 version in create mono dotnet. This is recently broken due to the Major version update to 9 while we have 8 hardcoded.

Test run: https://dev.azure.com/dnceng/internal/_build/results?buildId=2257289&view=results

Author:	LoopedBard3
Assignees:	LoopedBard3
Labels:	area-Infrastructure-mono
Milestone:	-

[cincuranet]

Isn't this where the framework variable from parameters should be used?

[LoopedBard3]

Isn't this where the framework variable from parameters should be used?

Updated to use this variable. Something of note, the framework here does not seem to have any actual impact on test framework stuff since we get that from the channel_map.