Drop python2 support from the CI

Since everyone seems to be doing it?

.github/workflows/ci.yml

@@ -18,25 +18,12 @@ jobs:
         -
             uses: actions/setup-python@v1
             with:
-                python-version: '3.x' 
+                python-version: '3.x'
         -   name: "Main Script"
             run: |
                 curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/prepare-and-run-flake8.sh
                 . ./prepare-and-run-flake8.sh "$(basename $GITHUB_REPOSITORY)" examples test
 
-    pytest2:
-        name: Pytest on Py2
-        runs-on: ubuntu-latest
-        steps:
-        -   uses: actions/checkout@v2
-        -   name: "Main Script"
-            run: |
-                sed 's/python=3/python=2.7/' .test-conda-env-py3.yml > .test-conda-env-py2.yml
-                grep -v mpi4py .test-conda-env-py2.yml > .test-conda-env.yml
-                CONDA_ENVIRONMENT=.test-conda-env.yml
-                curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-and-test-py-project-within-miniconda.sh
-                . ./build-and-test-py-project-within-miniconda.sh
-
     pytest3:
         name: Pytest on Py3
         runs-on: ubuntu-latest