Updating rel notes with issue numbers (#9461)

* Update 8.0.6.md

* Update 6.0.31.md

* Update 7.0.20.md

* Update 6.0.21.md

release-notes/6.0/6.0.21/6.0.21.md

@@ -99,7 +99,7 @@ You need [Visual Studio 17.3](https://visualstudio.microsoft.com) or later to us
 
 ## Feedback
 
-Your feedback is important and appreciated. We've created an issue at [dotnet/core #XXXX](https://github.com/dotnet/core/issues/XXXX) for your questions and comments.
+Your feedback is important and appreciated. We've created an issue at [dotnet/core #8673](https://github.com/dotnet/core/issues/8673) for your questions and comments.
 
 [blob-runtime]: https://dotnetcli.blob.core.windows.net/dotnet/Runtime/
 [blob-sdk]: https://dotnetcli.blob.core.windows.net/dotnet/Sdk/

release-notes/6.0/6.0.31/6.0.31.md

@@ -89,7 +89,7 @@ You need [Visual Studio 17.3](https://visualstudio.microsoft.com) or later to us
 
 ## Feedback
 
-Your feedback is important and appreciated. We've created an issue at [dotnet/core #xxxx](https://github.com/dotnet/core/issues/xxxx) for your questions and comments.
+Your feedback is important and appreciated. We've created an issue at [dotnet/core #9362](https://github.com/dotnet/core/issues/9362) for your questions and comments.
 
 [blob-runtime]: https://dotnetcli.blob.core.windows.net/dotnet/Runtime/
 [blob-sdk]: https://dotnetcli.blob.core.windows.net/dotnet/Sdk/

release-notes/7.0/7.0.20/7.0.20.md

@@ -61,7 +61,7 @@ You need [Visual Studio 17.4](https://visualstudio.microsoft.com) or later to us
 
 ## Feedback
 
-Your feedback is important and appreciated. We've created an issue at [dotnet/core #XXXX](https://github.com/dotnet/core/issues/XXXX) for your questions and comments.
+Your feedback is important and appreciated. We've created an issue at [dotnet/core #9362](https://github.com/dotnet/core/issues/9362) for your questions and comments.
 
 [blob-runtime]: https://dotnetcli.blob.core.windows.net/dotnet/Runtime/
 [blob-sdk]: https://dotnetcli.blob.core.windows.net/dotnet/Sdk/

release-notes/8.0/8.0.6/8.0.6.md

@@ -64,7 +64,7 @@ You need [Visual Studio 17.9](https://visualstudio.microsoft.com) or later to us
 
 ## Feedback
 
-Your feedback is important and appreciated. We've created an issue at [dotnet/core #XXXX](https://github.com/dotnet/core/issues/XXXX) for your questions and comments.
+Your feedback is important and appreciated. We've created an issue at [dotnet/core #9362](https://github.com/dotnet/core/issues/9362) for your questions and comments.
 
 [blob-runtime]: https://dotnetcli.blob.core.windows.net/dotnet/Runtime/
 [blob-sdk]: https://dotnetcli.blob.core.windows.net/dotnet/Sdk/