[Test] Mark new Interpreter/issue-85020 test as executable_test (#85790)

Otherwise, various [non-executable CI like Android
fail](https://ci.swift.org/job/oss-swift-package-swift-sdk-for-android/110/console).

Author: finagolfin

test/Interpreter/issue-85020.swift

@@ -2,6 +2,8 @@
 
 // https://github.com/swiftlang/swift/issues/85020
 
+// REQUIRES: executable_test
+
 struct Store {
   let theType: Any.Type