Delete dead sourceURLForBridge delegate chain

Summary:
`sourceURLForBridge:` has no callers: the factory reads `bundleURL` directly, and the default delegate's implementations only threw or forwarded to each other. Delete the protocol method with those implementations and the factory's dead configuration assignment. The `RCTJavaScriptLoader.h` import stays: removing it breaks every `RCTBridge.h` importer that uses the loader types.

Changelog:
[iOS][Removed] - Remove deprecated `RCTBridgeDelegate` `sourceURLForBridge:`

Differential Revision: D127294778

Author: christophpurrer

packages/react-native/Libraries/AppDelegate/RCTDefaultReactNativeFactoryDelegate.mm

@@ -6,8 +6,6 @@
  */
 
 #import "RCTDefaultReactNativeFactoryDelegate.h"
-#import <React/RCTBridge.h>
-#import <React/RCTJavaScriptLoader.h>
 #import <React/RCTRootView.h>
 #import <ReactCommon/RCTHost.h>
 #import "RCTAppSetupUtils.h"
@@ -29,13 +27,6 @@ @implementation RCTDefaultReactNativeFactoryDelegate {
 
 @synthesize dependencyProvider;
 
-- (NSURL *_Nullable)sourceURLForBridge:(nonnull RCTBridge *)bridge
-{
-  [NSException raise:@"RCTBridgeDelegate::sourceURLForBridge not implemented"
-              format:@"Subclasses must implement a valid sourceURLForBridge method"];
-  return nil;
-}
-
 - (UIViewController *)createRootViewController
 {
   return [UIViewController new];
@@ -132,11 +123,4 @@ - (Class)getModuleClassFromName:(const char *)name
   return nullptr;
 }
 
-- (void)loadSourceForBridge:(RCTBridge *)bridge
-                 onProgress:(RCTSourceLoadProgressBlock)onProgress
-                 onComplete:(RCTSourceLoadBlock)loadCallback
-{
-  [RCTJavaScriptLoader loadBundleAtURL:[self sourceURLForBridge:bridge] onProgress:onProgress onComplete:loadCallback];
-}
-
 @end

packages/react-native/Libraries/AppDelegate/RCTReactNativeFactory.mm

@@ -295,11 +295,6 @@ - (RCTRootViewFactory *)createRCTRootViewFactory
     [weakSelf.delegate customizeRootView:(RCTRootView *)rootView];
   };
 
-  configuration.sourceURLForBridge = ^NSURL *_Nullable(RCTBridge *_Nonnull bridge)
-  {
-    return [weakSelf.delegate bundleURL];
-  };
-
   if ([self.delegate respondsToSelector:@selector(extraModulesForBridge:)]) {
     configuration.extraModulesForBridge = ^NSArray<id<RCTBridgeModule>> *_Nonnull(RCTBridge *_Nonnull bridge)
     {

packages/react-native/Libraries/AppDelegate/RCTRootViewFactory.h

@@ -6,6 +6,7 @@
  */
 
 #import <React/RCTBridge.h>
+#import <React/RCTJavaScriptLoader.h>
 #import <React/RCTRootView.h>
 #import <React/RCTUtils.h>
 #import "RCTJSRuntimeConfiguratorProtocol.h"

packages/react-native/React/Base/RCTBridgeDelegate.h

@@ -13,17 +13,6 @@
 NS_ASSUME_NONNULL_BEGIN
 
 @protocol RCTBridgeDelegate <NSObject>
-#ifndef RCT_REMOVE_LEGACY_ARCH
-
-/**
- * The location of the JavaScript source file. When running from the packager
- * this should be an absolute URL, e.g. `http://localhost:8081/index.ios.bundle`.
- * When running from a locally bundled JS file, this should be a `file://` url
- * pointing to a path inside the app resources, e.g. `file://.../main.jsbundle`.
- */
-- (NSURL *__nullable)sourceURLForBridge:(RCTBridge *)bridge
-    __deprecated_msg("This API will be removed along with the legacy architecture.");
-#endif
 @end
 
 NS_ASSUME_NONNULL_END

packages/rn-tester/RNTester/SceneDelegate.mm

@@ -89,11 +89,6 @@ - (void)scene:(UIScene *)scene continueUserActivity:(NSUserActivity *)userActivi
   [RCTLinkingManager scene:scene continueUserActivity:userActivity];
 }
 
-- (NSURL *)sourceURLForBridge:(RCTBridge *)bridge
-{
-  return [self bundleURL];
-}
-
 - (NSURL *)bundleURL
 {
   return [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:kBundlePath];

scripts/cxx-api/api-snapshots/ReactAppleDebugCxx.api

@@ -2503,7 +2503,6 @@ protocol RCTBackedTextInputViewProtocol : public UITextInput {
 }
 
 protocol RCTBridgeDelegate : public NSObject {
-  public virtual NSURL* _Nullable sourceURLForBridge:(RCTBridge* bridge);
 }
 
 protocol RCTBridgeMethod : public NSObject {

scripts/cxx-api/api-snapshots/ReactAppleFrameworksCxx.api

@@ -2561,7 +2561,6 @@ protocol RCTBackedTextInputViewProtocol : public UITextInput {
 }
 
 protocol RCTBridgeDelegate : public NSObject {
-  public virtual NSURL* _Nullable sourceURLForBridge:(RCTBridge* bridge);
 }
 
 protocol RCTBridgeMethod : public NSObject {

scripts/cxx-api/api-snapshots/ReactAppleReleaseCxx.api

@@ -2503,7 +2503,6 @@ protocol RCTBackedTextInputViewProtocol : public UITextInput {
 }
 
 protocol RCTBridgeDelegate : public NSObject {
-  public virtual NSURL* _Nullable sourceURLForBridge:(RCTBridge* bridge);
 }
 
 protocol RCTBridgeMethod : public NSObject {