Kill processes after completing build and before publishing test results or artifacts (#7228)

- aspnet/AspNetCore-Internal#1735
- port dotnet/extensions@e2bb8ac1a0 fix into this repo
  - change `default-build.yml` instead of `azure-pipelines.yml`
  - make a couple of changes to `KillProcesses.ps1` (which I'll take back to Extensions)
- remove `ci-official.yml`

Author: dougbu

.azure/pipelines/ci-official.yml

@@ -121,9 +121,15 @@ jobs:
   - ${{ if eq(parameters.agentOs, 'Windows') }}:
     - script: .\$(BuildDirectory)\build.cmd -ci /p:SignType=$(_SignType) /p:Configuration=$(BuildConfiguration) $(BuildScriptArgs)
       displayName: Run build.cmd
+    - powershell: eng\scripts\KillProcesses.ps1
+      displayName: Kill processes
+      condition: always()
   - ${{ if ne(parameters.agentOs, 'Windows') }}:
     - script: ./$(BuildDirectory)/build.sh -ci -p:Configuration=$(BuildConfiguration) $(BuildScriptArgs)
       displayName: Run build.sh
+    - script: eng/scripts/KillProcesses.sh
+      displayName: Kill processes
+      condition: always()
   - task: PublishTestResults@2
     displayName: Publish test results
     condition: always()

.azure/pipelines/jobs/default-build.yml

@@ -0,0 +1,16 @@
+$ErrorActionPreference = 'Continue'
+
+taskkill /T /F /IM dotnet.exe
+taskkill /T /F /IM testhost.exe
+taskkill /T /F /IM iisexpress.exe
+taskkill /T /F /IM iisexpresstray.exe
+taskkill /T /F /IM w3wp.exe
+taskkill /T /F /IM msbuild.exe
+taskkill /T /F /IM vbcscompiler.exe
+taskkill /T /F /IM git.exe
+taskkill /T /F /IM vctip.exe
+taskkill /T /F /IM chrome.exe
+taskkill /T /F /IM h2spec.exe
+iisreset /restart
+
+exit 0

eng/scripts/KillProcesses.ps1

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+pkill dotnet || true
+exit 0