Revert repository configuration changes in versions/15/Makefile

- Restore LIBPG_QUERY_REPO to launchql/libpg_query.git
- Restore LIBPG_QUERY_TAG to fix/negative-int-pg15
- Keep memory configuration flags as intended

Co-Authored-By: Dan Lynch <pyramation@gmail.com>

Author: devin-ai-integration[bot]

versions/15/Makefile

@@ -6,8 +6,10 @@
 WASM_OUT_DIR := wasm
 WASM_OUT_NAME := libpg-query
 WASM_MODULE_NAME := PgQueryModule
-LIBPG_QUERY_REPO := https://github.com/pganalyze/libpg_query.git
-LIBPG_QUERY_TAG := 15-4.2.4
+# LIBPG_QUERY_REPO := https://github.com/pganalyze/libpg_query.git
+# LIBPG_QUERY_TAG := 15-4.2.4
+LIBPG_QUERY_REPO := https://github.com/launchql/libpg_query.git
+LIBPG_QUERY_TAG := fix/negative-int-pg15
 
 CACHE_DIR := .cache