get bwc version from latest 2.x

Signed-off-by: Hailong Cui <[email protected]>

build.gradle

@@ -637,8 +637,21 @@ task integTestRemote(type: RestIntegTestTask) {
 }
 
 // === Set up BWC tests ===
-
-String bwcVersionShort = "2.19.0"
+// get latest 2.x version from OpenSearch 2.x branch
+static def fetchVersionProperties() {
+    def url = 'https://raw.githubusercontent.com/opensearch-project/OpenSearch/refs/heads/2.x/buildSrc/version.properties'
+    def content = new URL(url).text
+    // Use regex to extract the version number
+    def matcher = content =~ /opensearch\s*=\s*(\d+\.\d+\.\d+)/
+    if (matcher.find()) {
+        def version = matcher.group(1)
+        println("Extracted latest 2.x version: $version")
+        return version
+    } else {
+        return "2.19.0"
+    }
+}
+String bwcVersionShort = fetchVersionProperties()
 String bwcVersion = bwcVersionShort + ".0"
 String baseName = "indexmanagementBwcCluster"