[DOM] Infer react-server entries bundles if not explicitly configured (#28795)

When packaging we want to infer that a bundle exists for a
`react-server` file even if it isn't explicitly configured. This is
useful in particular for the react-server entrypoints that error on
import that were recently added to `react-dom`

This change also cleans up a wayward comment left behind in a prior PR

DiffTrain build for [7f93cb41c8](https://github.com/facebook/react/commit/7f93cb41c8e1352eec158e508bc612025425266d)

compiled/facebook-www/REVISION

@@ -1 +1 @@
-f6131653570bbbf62d642ba9343b9cd0ab1ae97c
+7f93cb41c8e1352eec158e508bc612025425266d

compiled/facebook-www/ReactDOMTesting-dev.classic.js

@@ -36769,7 +36769,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-classic-45e82962";
+    var ReactVersion = "19.0.0-www-classic-47ca9f1a";
 
     function createPortal$1(
       children,
@@ -50441,7 +50441,7 @@ if (__DEV__) {
         NoEventPriority,
       findDOMNode: null,
       usingClientEntryPoint: false
-    }; // if (true) {
+    };
 
     {
       if (

compiled/facebook-www/ReactDOMTesting-dev.modern.js

@@ -46397,7 +46397,7 @@ if (__DEV__) {
       return root;
     }
 
-    var ReactVersion = "19.0.0-www-modern-0db632cf";
+    var ReactVersion = "19.0.0-www-modern-cb18514c";
 
     function createPortal$1(
       children,
@@ -48926,7 +48926,7 @@ if (__DEV__) {
         NoEventPriority,
       findDOMNode: null,
       usingClientEntryPoint: false
-    }; // if (true) {
+    };
 
     {
       if (