Bump dnspython from 2.6.1 to 2.7.0 (#2440)

* Bump dnspython from 2.6.1 to 2.7.0

Bumps [dnspython](https://github.com/rthalley/dnspython) from 2.6.1 to 2.7.0.
- [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/v2.6.1...v2.7.0)

---
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==2.7.0

---------

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/set.py

@@ -21,10 +21,11 @@ import itertools
 class Set:
     """A simple set class.
 
-    This class was originally used to deal with sets being missing in
-    ancient versions of python, but dnspython will continue to use it
-    as these sets are based on lists and are thus indexable, and this
-    ability is widely used in dnspython applications.
+    This class was originally used to deal with python not having a set class, and
+    originally the class used lists in its implementation.  The ordered and indexable
+    nature of RRsets and Rdatasets is unfortunately widely used in dnspython
+    applications, so for backwards compatibility sets continue to be a custom class, now
+    based on an ordered dictionary.
     """
 
     __slots__ = ["items"]
@@ -43,7 +44,7 @@ class Set:
                 self.add(item)  # lgtm[py/init-calls-subclass]
 
     def __repr__(self):
-        return "dns.set.Set(%s)" % repr(list(self.items.keys()))
+        return f"dns.set.Set({repr(list(self.items.keys()))})"  # pragma: no cover
 
     def add(self, item):
         """Add an item to the set."""