build: change spark-prove to use -j0 for all available cores

Author: abitofhelp

Makefile

@@ -356,7 +356,7 @@ spark-prove: ## Run SPARK PROVE formal verification
 		echo "$(RED)✗ SPARK project file not found: $(PROJECT_NAME)_spark.gpr$(NC)"; \
 		exit 1; \
 	fi
-	@cd $(TEST_DIR) && $(ALR) exec -- gnatprove -j12 -P ../$(PROJECT_NAME)_spark.gpr --mode=prove --level=2 2>&1; \
+	@cd $(TEST_DIR) && $(ALR) exec -- gnatprove -j0 -P ../$(PROJECT_NAME)_spark.gpr --mode=prove --level=2 2>&1; \
 	if [ $$? -eq 0 ]; then \
 		echo "$(GREEN)✓ SPARK PROVE verification passed$(NC)"; \
 	else \