🍒 [cxx-interop] Fix input header paths in a test

Explanation: There is a difference between the logic resolving modules
in upstream and downstream versions of the compiler this is why the
wrong path did not fail the CIs upstream. Having the correct path both
fixes downstream CIs and makes the tests more resilient to changes in
the lookup logic in the future.
Scope: Tests.
Risk: Low, test change only to fix CI.
Testing: No additional tests needed.
Issue: rdar://131629163
Reviewer: @egorzhdan
Original PR: swiftlang#75237

Author: Xazax-hun

test/Interop/Cxx/class/safe-use-of-returned-reference-with-borrowing.swift

@@ -1,12 +1,12 @@
 // RUN: rm -rf %t
 // RUN: split-file %s %t
-// RUN: %target-build-swift %t/test.swift -I %t -o %t/out -Xfrontend -enable-experimental-cxx-interop -O
+// RUN: %target-build-swift %t/test.swift -I %t/Inputs -o %t/out -Xfrontend -enable-experimental-cxx-interop -O
 // RUN: %target-codesign %t/out
 // RUN: %target-run %t/out
 
 // Verify that a non-const ref value parameter can't implicitly receive
 // aborrowed value.
-// RUN: %target-swift-frontend -DBORROW_PASS_TO_VALUE_PARAM -emit-ir -o /dev/null -I %t %t/test.swift -enable-experimental-cxx-interop -verify
+// RUN: %target-swift-frontend -DBORROW_PASS_TO_VALUE_PARAM -emit-ir -o /dev/null -I %t/Inputs %t/test.swift -enable-experimental-cxx-interop -verify
 
 // REQUIRES: executable_test