[FirebaseCore] Mark duplicate internal API as unavailable in Swift (#9812)

* Mark API as unavailable

* Kick off storage and functions CI as well

* [skip ci] Revert .github/workflows/storage.yml

* [skip ci] Revert .github/workflows/functions.yml

* [skip ci] Revert .github/workflows/functions.yml (2)

* [skip ci] Revert .github/workflows/storage.yml (2)

Author: ncooke3

FirebaseCore/Sources/FIRComponentContainerInternal.h

@@ -29,7 +29,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 /// Retrieves an instance that conforms to the specified protocol. This will return `nil` if the
 /// protocol wasn't registered, or if the instance couldn't be instantiated for the provided app.
-- (nullable id)instanceForProtocol:(Protocol *)protocol NS_SWIFT_NAME(instance(for:));
+- (nullable id)instanceForProtocol:(Protocol *)protocol
+    NS_SWIFT_UNAVAILABLE("Use `instance(for:)` from the FirebaseCoreExtension module instead.");
 
 /// Instantiates all the components that have registered as "eager" after initialization.
 - (void)instantiateEagerComponents;