Bump dnspython from 2.4.2 to 2.6.1 (#2264)

* Bump dnspython from 2.4.2 to 2.6.1

Bumps [dnspython](https://github.com/rthalley/dnspython) from 2.4.2 to 2.6.1.
- [Release notes](https://github.com/rthalley/dnspython/releases)
- [Changelog](https://github.com/rthalley/dnspython/blob/main/doc/whatsnew.rst)
- [Commits](https://github.com/rthalley/dnspython/compare/v2.4.2...v2.6.1)

---
updated-dependencies:
- dependency-name: dnspython
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update dnspython==2.6.1

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: JonnyWong16 <9099342+JonnyWong16@users.noreply.github.com>

[skip ci]

lib/dns/_asyncio_backend.py

@@ -7,7 +7,9 @@ import socket
 import sys
 
 import dns._asyncbackend
+import dns._features
 import dns.exception
+import dns.inet
 
 _is_win32 = sys.platform == "win32"
 
@@ -121,7 +123,7 @@ class StreamSocket(dns._asyncbackend.StreamSocket):
         return self.writer.get_extra_info("peercert")
 
 
-try:
+if dns._features.have("doh"):
     import anyio
     import httpcore
     import httpcore._backends.anyio
@@ -205,7 +207,7 @@ try:
                 resolver, local_port, bootstrap_address, family
             )
 
-except ImportError:
+else:
     _HTTPTransport = dns._asyncbackend.NullTransport  # type: ignore
 
 
@@ -224,14 +226,12 @@ class Backend(dns._asyncbackend.Backend):
         ssl_context=None,
         server_hostname=None,
     ):
-        if destination is None and socktype == socket.SOCK_DGRAM and _is_win32:
-            raise NotImplementedError(
-                "destinationless datagram sockets "
-                "are not supported by asyncio "
-                "on Windows"
-            )
         loop = _get_running_loop()
         if socktype == socket.SOCK_DGRAM:
+            if _is_win32 and source is None:
+                # Win32 wants explicit binding before recvfrom().  This is the
+                # proper fix for [#637].
+                source = (dns.inet.any_for_af(af), 0)
             transport, protocol = await loop.create_datagram_endpoint(
                 _DatagramProtocol,
                 source,
@@ -266,7 +266,7 @@ class Backend(dns._asyncbackend.Backend):
         await asyncio.sleep(interval)
 
     def datagram_connection_required(self):
-        return _is_win32
+        return False
 
     def get_transport_class(self):
         return _HTTPTransport