Remove pointless setters in GitReleaseAsset (#1527)

This is the only class that includes property setters for two of the
attributes, which are untested, and even if they were used, would have
no impact since there is no method to submit the changes back to GitHub.
Drop them.

Author: s-t-e-v-e-n-k

github/GitReleaseAsset.py

@@ -60,14 +60,6 @@ def name(self):
         self._completeIfNotSet(self._name)
         return self._name.value
 
-    @name.setter
-    def name(self, value):
-        """
-        :type: string
-        """
-        self._completeIfNotSet(self._name)
-        self._name.value = value
-
     @property
     def label(self):
         """
@@ -76,14 +68,6 @@ def label(self):
         self._completeIfNotSet(self._label)
         return self._label.value
 
-    @label.setter
-    def label(self, value):
-        """
-        :type: string
-        """
-        self._completeIfNotSet(self._label)
-        self._label.value = value
-
     @property
     def content_type(self):
         """

github/GitReleaseAsset.pyi

@@ -21,12 +21,8 @@ class GitReleaseAsset(CompletableGithubObject):
     def id(self) -> int: ...
     @property
     def label(self) -> str: ...
-    @label.setter
-    def label(self, value: str) -> None: ...
     @property
     def name(self) -> str: ...
-    @name.setter
-    def name(self, value: str) -> None: ...
     @property
     def size(self) -> int: ...
     @property