Builds failing to run due to missing .NET SDK

[ellahathaway]

Numerous pipelines and branches are failing due to missing .NET SDKs.

I'm seeing this issue in the following branches:

• release/10.0.1xx
• internal/release/10.0.1xx
• release/10.0.2xx
• release/8.0.1xx

Link to example failure: https://dev.azure.com/dnceng/internal/_build/results?buildId=2846374&view=logs&j=8e2906d7-a694-5f79-472d-c7a61446086d&t=81334588-2501-5097-4b75-17a53da5c2f6

[ellahathaway]

Similar to #5408, the .NET SDK is not being installed with eng/common/build.sh -bl --projects $(Build.SourcesDirectory)/test/Microsoft.DotNet.SourceBuild.Tests/Microsoft.DotNet.SourceBuild.Tests.csproj --restore.

[ellahathaway]

Here is the list of PRs:

• [main] Support shared .NET installation dotnet#3544
• [release/10.0.1xx] Support shared .NET installation dotnet#3518
• [release/10.0.2xx] Support shared .NET installation dotnet#3545
• [release/9.0.1xx] Support shared .NET installation - baseline update,… sdk#51908
• [release/8.0.1xx] Support shared .NET installation installer#20736

The fix has been merged into all relevant .NET branches, so I'm closing this issue.