Update openapi-generator.yml

Moving back to 18

Author: karen-avetisyan-mc

.github/workflows/openapi-generator.yml

@@ -26,10 +26,10 @@ jobs:
         with:
           name: generated-client
           path: java-client/
-      - name: Set up JDK 17
+      - name: Set up JDK 18
         uses: actions/setup-java@v3
         with:
-          java-version: '17'
+          java-version: '18'
           distribution: adopt
       - name: Cache local Maven repository
         uses: actions/cache@v3