github actions: runner upgrade (#375)

Co-authored-by: nithya <nithya.rajashekhar@smarkets.com>

.github/workflows/test.yml

@@ -13,13 +13,13 @@ env:
 
 jobs:
   test:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: ["3.8", "3.9"]
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install requirements