Pick the right OS version in KNN tests

Signed-off-by: Gulshan <[email protected]>

Author: kumargu

.github/workflows/security-knn-tests.yml

@@ -28,8 +28,7 @@ jobs:
       - id: plugin-availability-check
         name: "plugin check"
         run: |
-          opensearch_version=$(grep "System.getProperty(\"opensearch.version\", \"" build.gradle | grep '\([0-9]\|[.]\)\{5\}' -o)
-          opensearch_version=$opensearch_version".0-SNAPSHOT"
+          opensearch_version=$(./gradlew properties | grep -E '^version:' | awk '{print $2}')
           # we publish build artifacts to the below url 
           sec_plugin_url="https://aws.oss.sonatype.org/content/repositories/snapshots/org/opensearch/plugin/opensearch-security/"$opensearch_version"/"
           sec_st=$(curl -s -o /dev/null -w "%{http_code}" $sec_plugin_url)