Fix bug [966887] : FrameworksIndex files not cleaned up

[v-fuquanli]

Fix bug [966887] : FrameworksIndex files not cleaned up

The pipeline api-doc-tools-Official run successfully https://ceapex.visualstudio.com/Engineering/_build/results?buildId=1729303&view=results

Local test steps: 1.Prepare two versions of sdk as input

|_aspnetcore-7.0
 |-A.dependent.dll
|_aspnetcore-8.0
 |-A.dependent.dll

2.use below command to run mdoc fx-bootstrap -fx "C:\xxx\input" After running succesfully, the input folder will generate a frameworks.xml
3.use below command to run mdoc update -o "C:\xxx\output" -fx "C:\xxx\input" -- debug -index false -lang docid -lang vb.net -lang fsharp -L "C:\Program Files (x86)\Windows Kits\8.1\References" -L "C:\Program Files (x86)\Microsoft.NET\Primary Interop Assemblies\msdatasrc.dll" -L "C:\Program Files\Microsoft Visual Studio\2022\Professional\Common7\IDE\PublicAssemblies" -L "C:\Program Files\dotnet" --delete After running succefully, the output folder will generate some folder and xml. FrameworksIndex folder has generated two corresponding xml files

. At this point, our preparations are complete.
4.Delete a folder in the input folder, here we delete aspnetcore-7.0 to test，then execute the command in step 2.

5. Execute the command in step 3, aspnetcore-7.0.xml of output/framworksIndex was deleted.

[v-fuquanli]

FrameworksIndex folder is cleaned up when index is regenerated

[v-fuquanli]