Update SCI and SRM references in syntax generator to 9.0

[genlu]

In the PR upgrading our references to BCL assemblies, we had to pin syntax generator's references to SCI and SRM to 8.0, since this generator is built & consumed in our pipeline so it has to work with stock compiler in msbuild (currently shipped with 8.0). We need to upgrade it to 9 once 17.14 ships

[dotnet-issue-labeler]

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[dotnet-issue-labeler]

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