update for opensourcecobol4j-1.1.15 (#35)

Author: kio-watanabe

build-config.json

@@ -1,5 +1,5 @@
 {
-    "opensource_COBOL_4J_version": "1.1.14",
+    "opensource_COBOL_4J_version": "1.1.15",
     "Open_COBOL_ESQL_4J_version": "1.1.2",
-    "version_string_prefix": "20251031"
+    "version_string_prefix": "20251127"
 }