[ObjC] Avoid warning from Xcode 14.

Xcode 14 is warning:

```
warning: Run script build phase 'Script: Check Runtime Stamps' will be run during every build because it does not specify any outputs. To address this warning, either add output dependencies to the script phase, or configure it to run in every build by unchecking "Based on dependency analysis" in the script phase. (in target 'UnitTests' from project 'ProtocolBuffers_OSX')
```

This setting avoids that warning.

PiperOrigin-RevId: 488703116

objectivec/ProtocolBuffers_OSX.xcodeproj/project.pbxproj

@@ -700,6 +700,7 @@
 /* Begin PBXShellScriptBuildPhase section */
 		F4B62A781AF91F6000AFCEDC /* Script: Check Runtime Stamps */ = {
 			isa = PBXShellScriptBuildPhase;
+			alwaysOutOfDate = 1;
 			buildActionMask = 2147483647;
 			files = (
 			);

objectivec/ProtocolBuffers_iOS.xcodeproj/project.pbxproj

@@ -707,6 +707,7 @@
 /* Begin PBXShellScriptBuildPhase section */
 		F4B62A791AF91F7500AFCEDC /* Script: Check Runtime Stamps */ = {
 			isa = PBXShellScriptBuildPhase;
+			alwaysOutOfDate = 1;
 			buildActionMask = 2147483647;
 			files = (
 			);

objectivec/ProtocolBuffers_tvOS.xcodeproj/project.pbxproj

@@ -707,6 +707,7 @@
 /* Begin PBXShellScriptBuildPhase section */
 		F4B62A791AF91F7500AFCEDC /* Script: Check Runtime Stamps */ = {
 			isa = PBXShellScriptBuildPhase;
+			alwaysOutOfDate = 1;
 			buildActionMask = 2147483647;
 			files = (
 			);