Fix CI actions

Author: sximba

.github/workflows/ci.yml

@@ -5,6 +5,11 @@ on:
   pull_request:
   workflow_dispatch:
 
+env:
+  ES_7: "7.17.28"
+  ES_8: "8.18.2"
+  ES_9: "9.0.2"
+
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -15,7 +20,7 @@ jobs:
       matrix:
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
         django-version: ["4.2", "5.1", "5.2"]
-        es-version: ["7.17.28", "8.18.2", "9.0.2"]
+        es-version: [$ES_7, $ES_8, $ES_9]
         version: ["7.4", "8.0", "master"]
 
         exclude:
@@ -26,11 +31,11 @@ jobs:
           - python-version: "3.9"
             django-version: "5.2"
           - version: "8.0"
-            es-version: "7"
+            es-version: $ES_7
           - version: "master"
-            es-version: "7"
+            es-version: $ES_7
           - version: "master"
-            es-version: "8"
+            es-version: $ES_8
 
     steps:
       - name: Install and Run Elasticsearch