Remove legacy source provider sync path

dns_sync/normalizer.py

@@ -1,6 +1,16 @@
 import ipaddress
 import re
 
+def hostname_matches_domain(hostname: str, domain: str) -> bool:
+    """Match a domain apex and any subdomain, without suffix false positives."""
+    candidate = hostname.lower().rstrip(".")
+    if candidate.startswith("*."):
+        candidate = candidate[2:]
+
+    base = domain.lower().rstrip(".")
+    return candidate == base or candidate.endswith("." + base)
+
+
 _LABEL_RE = re.compile(r"^[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?$")