Remove dnspython<2.0.0 compatibility hacks from custom servers

isctest.asyncserver requires dnspython 2+ now.

(cherry picked from commit 8c2a72143c)

bin/tests/system/chain/ans3/ans.py

@@ -31,7 +31,7 @@ from isctest.asyncserver import (
 try:
     dns_namerelation_equal = dns.name.NameRelation.EQUAL
     dns_namerelation_subdomain = dns.name.NameRelation.SUBDOMAIN
-except AttributeError:  # dnspython < 2.0.0 compat
+except AttributeError:  # dnspython < 2.3.0 compat
     dns_namerelation_equal = dns.name.NAMERELN_EQUAL  # type: ignore
     dns_namerelation_subdomain = dns.name.NAMERELN_SUBDOMAIN  # type: ignore
 

bin/tests/system/chain/ans4/ans.py

@@ -34,11 +34,6 @@ from isctest.asyncserver import (
     ResponseAction,
 )
 
-try:
-    RdataType = dns.rdatatype.RdataType
-except AttributeError:  # dnspython < 2.0.0 compat
-    RdataType = int  # type: ignore
-
 
 class ChainNameGenerator:
     """
@@ -105,13 +100,13 @@ class RecordGenerator(abc.ABC):
 
     @classmethod
     def create_rrset(
-        cls, owner: dns.name.Name, rrtype: RdataType, rdata: str
+        cls, owner: dns.name.Name, rrtype: dns.rdatatype.RdataType, rdata: str
     ) -> dns.rrset.RRset:
         return dns.rrset.from_text(owner, 86400, dns.rdataclass.IN, rrtype, rdata)
 
     @classmethod
     def create_rrset_signature(
-        cls, owner: dns.name.Name, rrtype: RdataType
+        cls, owner: dns.name.Name, rrtype: dns.rdatatype.RdataType
     ) -> dns.rrset.RRset:
         covers = dns.rdatatype.to_text(rrtype)
         ttl = "86400"

bin/tests/system/isctest/asyncserver.py

@@ -53,13 +53,6 @@ import dns.tsig
 import dns.version
 import dns.zone
 
-try:
-    RdataType = dns.rdatatype.RdataType
-    RdataClass = dns.rdataclass.RdataClass
-except AttributeError:  # dnspython < 2.0.0 compat
-    RdataType = int  # type: ignore
-    RdataClass = int  # type: ignore
-
 
 _UdpHandler = Callable[
     [bytes, Tuple[str, int], asyncio.DatagramTransport], Coroutine[Any, Any, None]
@@ -291,11 +284,11 @@ class QueryContext:
         return self.alias or self.qname
 
     @property
-    def qclass(self) -> RdataClass:
+    def qclass(self) -> dns.rdataclass.RdataClass:
         return self.query.question[0].rdclass
 
     @property
-    def qtype(self) -> RdataType:
+    def qtype(self) -> dns.rdatatype.RdataType:
         return self.query.question[0].rdtype
 
 

bin/tests/system/qmin/qmin_ans.py

@@ -25,8 +25,6 @@ from isctest.asyncserver import (
     ResponseAction,
 )
 
-from isctest.compat import dns_rcode
-
 
 def log_query(qctx: QueryContext) -> None:
     """
@@ -66,7 +64,7 @@ class EntRcodeChanger(DomainHandler):
 
     @property
     @abc.abstractmethod
-    def rcode(self) -> dns_rcode:
+    def rcode(self) -> dns.rcode.Rcode:
         raise NotImplementedError
 
     async def get_responses(