[release/6.0] Define SystemReflectionMetadataStaticVersion to workaround source-build issues.

[MichaelSimons]

This fixes the underlying issue that manifested itself as #58800.

The core issue is that when building in source-build, the SystemReflectionMetadataVersion gets overridden to the source-built version (6.0) which causes assembly resolution issues impacting crossgen2. The long term solution is a 7.0 source-build feature which would eliminate the SystemReflectionMetadataVersion override because the dependency is not defined in the repo's Version.Details.xml file.

[MichaelSimons]

cc @dseefeld

[ghost]

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Issue Details

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This fixes the underlying issue that manifested itself as #58800.

The core issue is that when building in source-build, the SystemReflectionMetadataVersion gets overridden to the source-built version (6.0) which causes assembly resolution issues impacting crossgen2. The long term solution is a 7.0 source-build feature which would eliminate the SystemReflectionMetadataVersion override because the dependency is not defined in the repo's Version.Details.xml file.

Author:	MichaelSimons
Assignees:	-
Labels:	area-Infrastructure-libraries
Milestone:	-

[MichaelSimons]

@ViktorHofer - Can you tell me what ask/tell mode policies apply to this change? Thanks.

[ViktorHofer]

I'm not sure myself as this is a necessary change to ship .NET 6 built from source. @danmoseley would you know?

[danmoseley]

"Necessary infra changes to ship" is tell mode to tactics