Intellisense Files Missing Corresponding DLLs in Microsoft.AspNetCore.App.Ref

In reference to https://github.com/dotnet/runtime/issues/112102, it has been identified that not all IntelliSense files in the Microsoft.AspNetCore.App.Ref have corresponding DLLs.

This issue was originally surfaced by the source-build tests (see https://github.com/dotnet/runtime/issues/112102#issue-2828313150).

#### [IntelliSense files missing .dlls in the aspnetcore app ref - MSFT SDK](https://gist.github.com/ellahathaway/396fe3c7cdb6ba69728cdc2120535f80)

#### [IntelliSense files missing .dlls in the aspnetcore app ref - Source-Build SDK](https://gist.github.com/ellahathaway/8db7456f1ff26189a95181e7bd01952d)

I gathered the lists above with the following simple script:

```bash
#!/bin/bash
if [ "$#" -ne 2 ]; then
echo "Usage: $0 "
exit 1
fi

root_folder=$1
app_ref_folder=$2

cd "$root_folder" || exit

version=$(echo "$app_ref_folder" | grep -oP '\d+\.\d+\.\d+(-[a-zA-Z0-9.]+)?')

xmls=$(find "$app_ref_folder" -name "*.xml")
dlls=$(find "$app_ref_folder" -name "*.dll")

# Find xmls that don't have a corresponding dll
for xml in $xmls
do
dll=$(echo $xml | sed 's/.xml/.dll/')
if [[ ! $dlls =~ $dll ]]; then
# Replace the version and net10.0 with placeholders
xml=$(echo $xml | sed "s/$version/x.y.z/")
xml=$(echo $xml | sed 's/net10.0/netx.y/')
echo $xml
fi
done
```