Convert v2 doc warning into a note (#7867)

docs/source/beta_status.py

@@ -5,20 +5,20 @@
 class BetaStatus(Directive):
     has_content = True
     text = "The {api_name} is in Beta stage, and backward compatibility is not guaranteed."
+    node = nodes.warning
 
     def run(self):
         text = self.text.format(api_name=" ".join(self.content))
-        return [nodes.warning("", nodes.paragraph("", "", nodes.Text(text)))]
+        return [self.node("", nodes.paragraph("", "", nodes.Text(text)))]
 
 
 class V2BetaStatus(BetaStatus):
     text = (
-        "The {api_name} is in Beta stage, and while we do not expect major breaking changes, "
-        "some APIs may still change according to user feedback. Please submit any feedback you may have "
-        "in this issue: https://github.com/pytorch/vision/issues/6753, and you can also check "
-        "out https://github.com/pytorch/vision/issues/7319 to learn "
-        "more about the APIs that we suspect might involve future changes."
+        "The {api_name} is in Beta stage, and while we do not expect disruptive breaking changes, "
+        "some APIs may slightly change according to user feedback. Please submit any feedback you may have "
+        "in this issue: https://github.com/pytorch/vision/issues/6753."
     )
+    node = nodes.note
 
 
 def setup(app):