[Bug]: Compile error on Windows CLion, using MinGW toolchains

### Describe the issue

when I build protobuf on windows with CLion, i got the error 'cannot find -lrt' while linking protoc.exe, we should not link librt on Windows, right?
finally i found a typo in absl/base/CMakeLists.txt:230
`$<$:-lrt>` which should be `$<$:-lrt>`

### Steps to reproduce the problem

cmake build args:
-Dprotobuf_BUILD_SHARED_LIBS=OFF
-Dprotobuf_BUILD_TESTS=OFF
-Dprotobuf_BUILD_CONFORMANCE=OFF

### What version of Abseil are you using?

master

### What operating system and version are you using?

Windows 10

### What compiler and version are you using?

MinGW gcc version 11.2.0

### What build system are you using?

CMake 3.26.4

### Additional context

_No response_