remove MSVC100/vcexpress2010 from CI, at least for now

Due to failing installation of VC express 2010, that version isn't
being tested anyway, and is just producing errors.

If we work out a solution for the missing download from Microsoft
we can reinstate it, but at this point it's just noise
reducing the utility CI gives us.

This does not make VC2010 unsupported, it's purely a CI change.

.github/workflows/testsuite.yml

@@ -283,50 +283,6 @@ jobs:
 
   #===============================================
 
-  windows-msvc100:
-    name: "Windows msvc100"
-    runs-on: windows-latest
-    timeout-minutes: 120
-    needs: sanity_check
-    if: needs.sanity_check.outputs.run_all_jobs == 'true'
-
-    env:
-      PERL_SKIP_TTY_TEST: 1
-      CONTINUOUS_INTEGRATION: 1
-
-    steps:
-      - run: git config --global core.autocrlf false
-      - uses: actions/checkout@v2
-        with:
-          fetch-depth: 10
-      - uses: actions/cache@v2
-        with:
-          path: |
-            ${{ github.workspace }}\choco-cache
-          key: v2-msvc100
-      - name: Set up MSVC100
-        run: |
-          choco config set cacheLocation "${{ github.workspace }}\choco-cache"
-          choco install vcexpress2010
-      - name: Help
-        shell: cmd
-        run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvarsall.bat" /help
-      - name: Build
-        shell: cmd
-        run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvarsall.bat" x86
-          cd win32
-          nmake CCTYPE=MSVC100 WIN64=undef
-      - name: Run Tests
-        shell: cmd
-        run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvarsall.bat" x86
-          cd win32
-          nmake CCTYPE=MSVC100 WIN64=undef test
-
-  #===============================================
-
   mingw64:
     name: "Windows mingw64"
     runs-on: windows-latest