bump greenlet, numpy, remove support for 3.8

Author: MehulBatra

.github/workflows/python-ci.yml

@@ -34,7 +34,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python: ['3.8', '3.9', '3.10', '3.11']
+        python: ['3.9', '3.10', '3.11','3.12']
 
     steps:
     - uses: actions/checkout@v4