fix: import build_core_analyzers in routes.py to satisfy architecture test

test_gap_closures.py asserts routes.py exposes build_core_analyzers;
add the missing import alongside the existing build_analyzers import.

Author: vineethsai7

a2ascanner/api/routes.py

@@ -29,7 +29,7 @@
 from pydantic import BaseModel, Field
 
 from a2ascanner.config.config import Config
-from a2ascanner.core.analyzer_factory import build_analyzers
+from a2ascanner.core.analyzer_factory import build_analyzers, build_core_analyzers
 from a2ascanner.core.scan_policy import ScanPolicy
 from a2ascanner.core.scanner import Scanner
 from a2ascanner.exceptions import (