Remove 3.9, 3.11-dev and 3.7 test versions

Redo testing versions to reduce cpu use:

From pypi downloads, 3.8, 3.9 and 3.10 are all in the vicinity of 30%
over past 120 days.

Test the edges of the range 3.8/3.10. Skip 3.9.

Downloads for 3.7 is at 0, don't bother testing.

3.11 is tested, so we don't need to test 3.11-dev.

Test 3.6 and 3.12-dev since they are the minimum/maximum version we
support.

Author: rouilj

.github/workflows/ci-test.yml

@@ -48,9 +48,9 @@ jobs:
         python-version:
           - "2.7"
           - "3.10"
-          - "3.9"
+          # - "3.9"
           - "3.8"
-          - "3.7"
+          # - "3.7"
           - "3.11"
 
         # use for multiple os or ubuntu versions
@@ -66,8 +66,8 @@ jobs:
             - python-version: 3.12-dev
               os: ubuntu-22.04
               experimental: [true]
-            - python-version: 3.11-dev
-              os: ubuntu-20.04
+            #- python-version: 3.11-dev
+            #  os: ubuntu-20.04
             # 3.6 not available on new 22.04 runners, so run on 20.04 ubuntu
             - python-version: 3.6
               os: ubuntu-20.04