azure CI: remove vs2017 tests without replacement now that the image is deleted

The Windows 2016 images have been deprecated for a while now and
regularly browning out. There's no viable replacement for testing that
we can generate a usable `--backend=vs2017` project, so we cannot
migrate this to anything else.

The deprecated images are finally fully removed. See
https://github.com/actions/virtual-environments/issues/5403

And now we get universal red CI, we cannot just wait for the brownout to
end to get a tiny little bit of final testing.

Simply remove the jobs so that we can tell if all the CI that actually
runs, is passing.

azure-pipelines.yml

@@ -54,65 +54,6 @@ variables:
 
 jobs:
 
-- job: vs2017
-  timeoutInMinutes: 120
-  pool:
-    vmImage: VS2017-Win2016
-
-  strategy:
-    matrix:
-        vc2017x86ninja:
-          arch: x86
-          compiler: msvc2017
-          backend: ninja
-          MESON_RSP_THRESHOLD: 0
-          # "Compiler ifort can not compile programs"
-          ifort: false
-        vc2017x64vs:
-          arch: x64
-          compiler: msvc2017
-          backend: vs2017
-          # this causes tons of C projects to error with:
-          # "The syntax of the command is incorrect"
-          ifort: false
-        clangclx64ninja:
-          arch: x64
-          compiler: clang-cl
-          backend: ninja
-          ifort: true
-
-  steps:
-  - task: Cache@2
-    inputs:
-      path: C:\Program Files (x86)\Intel\oneAPI
-      key: '"install" | "$(WINDOWS_HPCKIT_URL)" | "$(WINDOWS_FORTRAN_COMPONENTS)" | "compiler" | ci/intel-scripts/cache_exclude_windows.sh'
-      cacheHitVar: CACHE_RESTORED
-    condition: eq(variables.ifort, 'true')
-  - script: ci/intel-scripts/install_windows.bat $(WINDOWS_HPCKIT_URL) $(WINDOWS_FORTRAN_COMPONENTS)
-    displayName: install ifort
-    condition: and(ne(variables.CACHE_RESTORED, 'true'), eq(variables.ifort, 'true'))
-  - bash: ci/intel-scripts/cache_exclude_windows.sh
-    displayName: exclude unused files from cache
-    condition: and(ne(variables.CACHE_RESTORED, 'true'), eq(variables.ifort, 'true'))
-  - task: UsePythonVersion@0
-    inputs:
-      versionSpec: '3.7'
-      addToPath: true
-      architecture: 'x64'
-  - task: BatchScript@1
-    displayName: insert ifort into environment
-    inputs:
-      filename: ci/intel-scripts/activate_windows.bat
-      arguments: vs2019
-      modifyEnvironment: True
-    condition: eq(variables.ifort, 'true')
-  - task: PowerShell@2
-    inputs:
-      targetType: 'filePath'
-      filePath: .\ci\run.ps1
-    env:
-      MESON_CI_JOBNAME: azure-$(System.JobName)
-
 - job: vs2019
   timeoutInMinutes: 120
   pool: