[mlir] Fix MLIRTestDialect dependency in MLIRTestIR

This is a test library which is not part of libMLIR, so it should
use normal LINK_LIBS instead of mlir_target_link_libraries.

This fixes an issue introduced in llvm#123910 and follows up on the
fix in llvm#125004, which added the library to DEPENDS, which is not
sufficient.

Author: nikic

mlir/test/lib/IR/CMakeLists.txt

@@ -27,13 +27,15 @@ add_mlir_library(MLIRTestIR
   TestVisitorsGeneric.cpp
 
   EXCLUDE_FROM_LIBMLIR
+
+  LINK_LIBS PUBLIC
+  MLIRTestDialect
   )
 mlir_target_link_libraries(MLIRTestIR PUBLIC
   MLIRPass
   MLIRBytecodeReader
   MLIRBytecodeWriter
   MLIRFunctionInterfaces
-  MLIRTestDialect
   )
 
 target_include_directories(MLIRTestIR