[OSLog] Remove the dependency on _Concurrency

_Concurrency is not used in the module, and having it as a dependency causes a ninja error when trying to build stdlib without `-D SWIFT_ENABLE_EXPERIMENTAL_CONCURRENCY=YES`:

```
ninja: error: 'stdlib/private/OSLog/swift_Concurrency-swiftmodule-macosx-arm64', needed by 'stdlib/private/OSLog/OSX/arm64/OSLogTestHelper.o', missing and no known rule to make it
```

Author: egorzhdan

stdlib/private/OSLog/CMakeLists.txt

@@ -14,10 +14,10 @@ add_swift_target_library(swiftOSLogTestHelper
   OSLogPrivacy.swift
   OSLogFloatFormatting.swift
 
-  SWIFT_MODULE_DEPENDS_IOS Darwin _Concurrency
-  SWIFT_MODULE_DEPENDS_OSX Darwin _Concurrency
-  SWIFT_MODULE_DEPENDS_TVOS Darwin _Concurrency
-  SWIFT_MODULE_DEPENDS_WATCHOS Darwin _Concurrency
+  SWIFT_MODULE_DEPENDS_IOS Darwin
+  SWIFT_MODULE_DEPENDS_OSX Darwin
+  SWIFT_MODULE_DEPENDS_TVOS Darwin
+  SWIFT_MODULE_DEPENDS_WATCHOS Darwin
   TARGET_SDKS ALL_APPLE_PLATFORMS
   SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
   INSTALL_IN_COMPONENT never_install