Install elasticsearch-py v8 for testing against Elasticsearch 8

.github/workflows/test.yml

@@ -264,7 +264,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install -e .[testing]
           pip install "${{ matrix.django }}"
-          pip install "elasticsearch>=7,<8"
+          pip install "elasticsearch>=8,<9"
           pip install certifi
       - name: Test
         run: |

tox.ini

@@ -37,7 +37,7 @@ deps =
     elasticsearch6: certifi
     elasticsearch7: elasticsearch>=7,<8
     elasticsearch7: certifi
-    elasticsearch8: elasticsearch>=7,<8
+    elasticsearch8: elasticsearch>=8,<9
     elasticsearch8: certifi
 
 setenv =