meson: add missing nlohmann dependencies to tests

Without it there are build failures because the include search path is
wrong in subproject mode.

Change-Id: I49ee9aab900a41ae91dccc43eccc68321f9d973a
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/requester/test/meson.build b/requester/test/meson.build
index 1f5fe17..74caa3e 100644
--- a/requester/test/meson.build
+++ b/requester/test/meson.build
@@ -17,6 +17,7 @@
                          gtest,
                          gmock,
                          libpldm_dep,
+                         nlohmann_json,
                          phosphor_dbus_interfaces,
                          sdbusplus,
                          sdeventplus,