The Enterprise Windows 2008R2 build variant runs a number of Evergreen tasks that appear (at least empirically) to be redundant with the list of tasks that run on some of the required Linux build variants. We should create a new variant with a task list similar to the following

- name: enterprise-windows-64-2k8-required
  display_name: "! Enterprise Windows 2008R2"
  modules: 
  - enterprise
  run_on: 
  - windows-64-vs2017-test
  expansions: ...  # Use an anchor/alias to avoid duplicating these
  display_tasks: 
  - *dbtest
  tasks: 
  - name: compile_TG
    requires: 
    - name: burn_in_tests_gen
    - name: verify_pip
    distros: 
    - windows-64-vs2017-compile
  - name: burn_in_tests_gen
  - name: verify_pip
  - name: buildscripts_test
  - name: dbtest_TG
    distros: 
    - windows-64-vs2017-compile
  - name: noPassthrough_gen

and update the display_name of the enterprise-windows-64-2k8 build variant to be "* Enterprise Windows 2008R2" in order to reflect it has a batchtime of 1 hour but isn't a required build variant. The definition of the required alias in the Evergreen database must also be updated to include enterprise-windows-64-2k8-required rather than enterprise-windows-64-2k8.