cmake: fix fmt linking when found

This is a new attempt at #4206 that shouldn't break windows builds.

If someone else could test on windows, it would be much appreciated.
Previously, the build bot passed but the actual builds failed.

src/common/CMakeLists.txt

@@ -191,5 +191,9 @@ endif()
 create_target_directory_groups(common)
 find_package(Boost 1.71 COMPONENTS context headers REQUIRED)
 
-target_link_libraries(common PUBLIC ${Boost_LIBRARIES} fmt::fmt microprofile)
+if (fmt_FOUND)
+    target_link_libraries(common PUBLIC ${Boost_LIBRARIES} fmt microprofile)
+else()
+    target_link_libraries(common PUBLIC ${Boost_LIBRARIES} fmt::fmt microprofile)
+endif()
 target_link_libraries(common PRIVATE lz4::lz4 zstd::zstd xbyak)