Update build badge links (#6589)

We changed build definitions months and months ago, and should update the links.

README.md

@@ -10,23 +10,23 @@ The [changelog](documentation/Changelog.md) has detailed information about chang
 
 The current development branch is `main`. Changes in `main` will go into a future update of MSBuild, which will release with Visual Studio 17.0 and a corresponding version of the .NET Core SDK.
 
-[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=main)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=86&branchName=main)
+[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=main)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=887&branchName=main)
 
 We have forked for MSBuild 16.11 in the branch [`vs16.11`](https://github.com/Microsoft/msbuild/tree/vs16.11). Changes to that branch need special approval.
 
-[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.11)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=86&branchName=vs16.11)
+[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.11)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=887&branchName=vs16.11)
 
 MSBuild 16.9 builds from the branch [`vs16.9`](https://github.com/dotnet/msbuild/tree/vs16.9). Only high-priority bugfixes will be considered for servicing 16.9.
 
-[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.9)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=86&branchName=vs16.9)
+[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.9)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=887&branchName=vs16.9)
 
 MSBuild 16.7 builds from the branch [`vs16.7`](https://github.com/dotnet/msbuild/tree/vs16.7). Only high-priority bugfixes will be considered for servicing 16.7.
 
-[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.7)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=86&branchName=vs16.7)
+[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.7)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=887&branchName=vs16.7)
 
 MSBuild 16.4 builds from the branch [`vs16.4`](https://github.com/dotnet/msbuild/tree/vs16.4). Only high-priority bugfixes will be considered for servicing 16.4.
 
-[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.4)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=86&branchName=vs16.4)
+[![Build Status](https://dev.azure.com/dnceng/public/_apis/build/status/Microsoft/msbuild/msbuild-pr?branchName=vs16.4)](https://dev.azure.com/dnceng/public/_build/latest?definitionId=887&branchName=vs16.4)
 
 MSBuild 15.9 builds from the branch [`vs15.9`](https://github.com/dotnet/msbuild/tree/vs15.9). Only very-high-priority bugfixes will be considered for servicing 15.9.