Bump nightly version in xcode projects (#9790)

Author: shoumikhin

examples/demo-apps/apple_ios/ExecuTorchDemo/ExecuTorchDemo.xcodeproj/project.pbxproj

@@ -806,7 +806,7 @@
 			isa = XCRemoteSwiftPackageReference;
 			repositoryURL = "https://github.com/pytorch/executorch";
 			requirement = {
-				branch = "swiftpm-0.6.0";
+				branch = "swiftpm-0.7.0.20250401";
 				kind = branch;
 			};
 		};

examples/demo-apps/apple_ios/LLaMA/LLaMA.xcodeproj/project.pbxproj

@@ -852,7 +852,7 @@
 			isa = XCRemoteSwiftPackageReference;
 			repositoryURL = "https://github.com/pytorch/executorch";
 			requirement = {
-				branch = "swiftpm-0.6.0";
+				branch = "swiftpm-0.7.0.20250401";
 				kind = branch;
 			};
 		};

examples/demo-apps/react-native/rnllama/ios/rnllama.xcodeproj/project.pbxproj

@@ -947,7 +947,7 @@
 			isa = XCRemoteSwiftPackageReference;
 			repositoryURL = "https://github.com/pytorch/executorch.git";
 			requirement = {
-				branch = "swiftpm-0.6.0";
+				branch = "swiftpm-0.7.0.20250401";
 				kind = branch;
 			};
 		};